Answer:
4.2 g
Explanation:
The VOLUME of the ring is 4.2 - 4.0 = .2 ml = .2 cm^3
the MASS of the ring is this times the density
.2 cm^3 * 21 g/cm^3 = 4.2 g
Answer:
the answer is c
Explanation:
density is mass/volume
so mass=density × volume
but we take the change is volume that is v2-v2=4.2-4=0.2ml
but the density is in gm/cm^3 so we should convert ml into cm^3. eventually they are equal so mass=21×0.2=4.2
Assume that a normal curve is a good model for this data set. If 10,000 more observations were collected, what percentage of the observations would be greater than 98.02? In other words, what percentage of the area under the normal distribution curve would lie above 98.02 on the x-axis?
A) 5.9%
B) 2.96%
C) 2.5%
D) 0.0%
The percentage of the area under the normal distribution curve would lie above 98.02 on the x-axis is 2.5 % , option C is the answer.
What is Normal Distribution ?Normal Distribution is a probability distribution which is symmetric about the mean , The frequency is more near the mean and less far from the mean.
It is given in the data that
10,000 more observations were collected
the percentage of the observations would be greater than 98.02 = ?
According to the 68-95-99.7 rule,
It states that approximately
68% of the observations lie within σ of µ
95% of the observations lie within 2σ of µ.
99.7% of the observations lie within 3σ of µ.
The percentage of the observation between various intervals is attached in the image in the answer.
2.1 percent of the population is distributed in the intervals between two and three standard deviations , which is the zone above 2SD and below 3SD.
As 2.1 % is approximate , Therefore from the given option , 2.5%
The percentage of the area under the normal distribution curve would lie above 98.02 on the x-axis is 2.5 % , option C is the answer.
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Predict the shape of the molecule.
The Correct option is A. octahedral
because the molecule has 6 sigma bonds that results into sp³d² hybridization.
and octahedral structure is formed
Answer:
Octahedral
Explanation:
You have a atom connected to 6 others and each of the bonds are similar
What are the rows of the periodic table called?
A. Periods
B. Elements
C. Atoms
D. Groups
Answer:
i believe its called A. periods
If winds blow against a mountain from the south, then on which slope would you find the least precipitation?
The northern slope will have the least precipitation if winds blow against a mountain from the south.
What is Slope?This is referred to as the degree of steepness on a surface such as rocky areas etc.
When wind blows on the southern part of a mountains, it gets stuck which is why the northern slope have the least precipitation.
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How many moles are in 24 g of carbon
Answer:
[tex]\fbox {2 moles}[/tex]
Explanation:
Relation between grams of Carbon and moles :
[tex]\fbox {12 g Carbon = 1 mole}[/tex]
Multiply both sides by 2 :
⇒ 1 x 2 moles = 12 x 2 g
⇒ 2 moles = 24 g
Which of the following is the electron configuration of an atom in the ground state?
(a) 1s2 2s1
(b) 1s2 2s2 2p5 3s2
(c) 1s2 2s1 2p6
(d) 1s1 2s2
Answer:
(a) 1s2 2s1
Explanation:
Electron configurations of atoms are in their ground state when the electrons completely fill each orbital before starting to fill the next orbital.
Understanding the notationIt's important to know how to read and interpret the notation.
For example, the first part of option (a) says "1s2"
The "1" means the first level or shellThe "s" means in an s-orbitalThe "2" means there are 2 electrons in that orbitalOther things to know about electron orbitalsIt important to know which orbitals are in each shell:
In level 1, there is only an s-orbitalIn level 2, there is an s-orbital and a p-orbitalin level 3, there is an s-orbital, a p-orbital, and a d-orbital (things get a little tricky when the d-orbitals get involved, but this problem is checking on the basic concept -- not the higher level trickery)So, it's also important to know how many electrons can be in each orbital in order to know if they are full or not. The electrons should fill up these orbitals for each level, in this order:
s-orbitals can hold 2p-orbitals can hold 6d-orbitals can hold 10 (but again, that's beyond the scope of this problem)Examining how the electrons are filling the orbitalsFor option (a):
the 1s orbital is filled with 2, andthe 2s orbital has a single electron in it with no other orbitals involved.This is in it's ground state.
For option (b):
the 1s orbital is filled with 2, the 2s orbital is filled with 2,the 2p orbital has 5 (short of a full 6), andthe 3s orbital has a single electron in it.Because the 3s orbital has an electron, but the lower 2p before it isn't full. This is NOT in it's ground state.
For option (c):
the 1s orbital is filled with 2, the 2s orbital has 1 (short of a full 2), andthe 2p orbital is filled with 6Although the 2p orbital is full, since the 2s orbital before it was not yet full, this is NOT in it's ground state.
For option (d):
the 1s orbital has 1 (short of a full 2), andthe 2s orbital is filled with 2Again, despite that the final orbital (in this case, the 2s orbital), is full, since the 1s orbital before it was not yet full, this is NOT in it's ground state.
A student uses a solution of 1.2 molar sodium hydroxide (NaOH) to calculate the concentration of a solution of sulfuric acid (H2SO4). She records a neutral pH after adding 20 mL of the sodium hydroxide solution to 50 mL of the sulfuric acid solution.
What is the concentration of the sulfuric acid solution?
A.
0.24 M
B.
0.12 M
C.
2.1 M
D.
1.0 M
E.
0.48 M
From the calculations, the concentration of the acid is 0.24 M.
What is neutralization?The term neutralization has to do with a reaction in which an acid and a base react to form salt and water only.
We have to use the formula;
CAVA/CBVB = NA/NB
CAVANB =CBVBNA
The equation of the reaction is; 2NaOH + H2SO4 ----> Na2SO4 + 2H2O
CA = ?
CB = 1.2 M
VA = 50 mL
VB = 20 mL
NA = 1
NB = 2
CA = CBVBNA/VANB
CA = 1.2 M * 20 mL * 1/ 50 mL * 2
CA = 0.24 M
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Corrosion may be regarded as the destruction of metal by:
Electrochemical action
Hydroelectric action
Electromechanical action
All of the above
Avogadro's number is the number of atoms or molecules in one mole of any substance. In other words, a mole is 6.02X1023 of some chemical unit. The size of the chemical unit does not change Avogadro’s number. An analogy can be made using eggs. You can buy small, medium, or large eggs. The size of the eggs doesn’t affect how many eggs are in one dozen. Similarly, the size of the representative particle doesn’t affect how many are in one mole. Describe your own analogy to show the relationship between moles and the size of representative particles.
A cubic meter of air was sampled at 1.0 ATM and 40 C.
An ion chromatographic analysis of that sample found it to contain 12 micrograms of NO2.
How many ppb of NO2 is in the air?
The amount of nitrogen oxide in the air sample is determined as 7.01 ppb.
Amount of Nitrogen oxide in the air
The amount of Nitrogen oxide (NO2) in the air in parts per billion (ppb) is calculated as follows;
12 micrograms of NO2 = 12 μg = 12 x 10⁻⁶ g
PV = nRT
V = nRT/P
Where;
V is volume of NO2 gasn is number of moles of NO2 gasT is temperature = 40 C = 313 Kn = m/M
M = molar mass of NO2 = 46
n = 12 x 10⁻⁶/46
n = 2.73 x 10⁻⁷ mole
V = (2.73 x 10⁻⁷ x 0.082057 x 313)/(1)
V = 7.01 x 10⁻⁶ L
V = 7.01 x 10⁻⁹ m³
Amount of NO2 In parts per billion= (Volume of NO2)/(volume of air) x 10⁹
= (7.01 x 10⁻⁹)/(1) x 10⁹
= 7.01 ppb
Thus, the amount of nitrogen oxide in the air sample is determined as 7.01 ppb.
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11C. Potassium hydrogen phthalate is a solid, monoprotic acid frequently used in the laboratory to standardize strong base solutions. It has the unwieldy formula of KHC8H4O4. This is often written in shorthand notation as KHP .If 3.41 grams of KHC are needed to exactly neutralize 31.2 mL of a potassium hydroxide solution, what is the concentration of the base solution?
13B.
H3AsO4 + H2C2O4—--------2CO2 + H3AsO3+ H2O
In the above redox reaction, use oxidation numbers to identify the element oxidized, the element reduced, the oxidizing agent and the reducing agent.
name of the element oxidized:
name of the element reduced:
formula of the oxidizing agent:
formula of the reducing agent:
For the reactants,
The oxidation number of hydrogen = +1The oxidation number of oxygen = -2The oxidation number of arsenic = +5The oxidation number of carbon = +3For the products,
The oxidation number of hydrogen = +1The oxidation number of oxygen = -2The oxidation number of arsenic = +3The oxidation number of carbon = +4Here, arsenic (+5 to +3) and carbon (+3 to +4) are the only oxidation numbers changing.
Note that an increase in oxidation number means electrons are lost. Thus oxidation is occurring, and a decrease in oxidation number means electrons are being gained, and thus reduction is occurring.
Also, the compound that contains the element being oxidized is the reducing agent, and the compound that contains the element being reduced is the oxidizing agent.
So, the answers are:
name of the element oxidized: Carbon
name of the element reduced: Arsenic
formula of the oxidizing agent: [tex]\text{H}_{3}\text{AsO}_{4}[/tex]
formula of the reducing agent: [tex]\text{H}_{2}\text{C}_{2}\text{O}_{4}[/tex]
What is the molar concentration of Zn2+ ions in a solution, if the electrode potential value is 59mV less than the standard electrode potential value at 298 K?
Molar concentration of Zn2+ions in a solution is 3.481 mol/lit
The electrode potential value is 59mV
Temperature=298k
What is electrode potential?
It is a force of galvanic cell. basically it is the difference between an electrolyte and electrode.equation formed- Zn → Zn2+ + 2e
from Nernst equation-
E=E cell - 0.059 log [Zn2+]
[zn2+]=3.481 mol/lit
hence, Molar concentration of Zn2+ions in a solution is 3.481 mol/lit
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A boy throws a stone vertically up into the air. What are the energy changes that take place as the stone falls to the ground?
Answer/Explanation:
The boy's muscle energy changes into potential energy due to the height. it then converts into kinetic energy as it goes further upwards into the air.
How much 5.50M NaOH must be added to 680.0 mL of a buffer that is 0.0215 M acetic acid and 0.0270 M sodium acetate to raise the pH to 5.75?
5.50M NaOH must be added to 680.0 mL of a buffer, The amount of NaOH is mathematically given as
V=2.107mL
What is the volume of 5.50M NaOH?Generally, the equation for Chemical Reaction is mathematically given as
CH3COOH+OH^{-} ⇄ CHCOO^{-} + H2O
Therefore
pka=-log(1.8*10{-5})
pKa=5-0.25527
pKa=4.3447
Hence
[tex]pH=pKa+log\frac{CH3COO}{CH3COOH}\\\\0.75=4.7447+log\frac{0.01564+x}{0.01428-x}[/tex]
x=0.0115898
Volume of NaOH
V=0.0021072L
V=2.107mL
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If a snail crawls at a rate of 228.16cm/s, what is its speed in miles per hour?
If a snail crawls at a rate of 228.16cm/s, Its speed in miles per hour will 5.10 miles/hour
What is speed ?
The rate at which someone or something moves or operates or is able to move or operate.
Snail covers distance in 1 seconds = 228.16 cm
It covers in 60 seconds (1 min) = 228.16 cm x 60 = 6mtrs
It covers in 60 minutes (1 hour) = 228.16 cm x 60 x 60 = 821376 cm
Now, lets convert cm to miles :
As, 1 cm = 6.21371 x 10⁻⁶ miles
Thus, 821376 cm = 5.10 miles
hence, If a snail crawls at a rate of 228.16cm/s, Its speed in miles per hour will 5.10 miles/hour
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describe 2 ways of salting out proteins
The phenomenon known as "salting-out" occurs at very high ionic strengths, when protein solubility declines as ionic strength rises. As a result, salting out may be used to segregate proteins according to how soluble they are in salt solutions.
Because large levels of sodium chloride disturb the bonds and structure of the active site, the rate of enzyme activity will gradually decrease as the concentration of sodium chloride rises. As a result, some of the active sites get denaturized and the starch loses its ability to attach to them. As more enzymes get denatured and eventually cease to function, enzyme activity will steadily wane.
A hydrocarbon contains 87,8% carbon and
12.2% hydrogen by mass. Its empirical
formula is?
C= 87.8 : 12 = 7.316
H= 12.2 : 1 = 12.2
C : H = 1 : 1.667 = 3 : 5
C₃H₅
Plutonium-239 undergoes alpha decay and has a half-life of 24,000 years. After 72,000 years, how much of an initial 100.0 g sample will remain?
A. none
B. 50.0 g
C. 25.0 g
D. 12.5 g
What is the role of a catalyst in a chemical reaction?
A increase the concentration of reactants
B increase the rate of the reaction
C increase the temperature of a reaction
D increase the pressure applied to the reaction
A catalyst is a substance that increases the rate of a chemical reaction by lowering the activation energy without itself being consumed by the reaction.
A group of students measure the length of a pencil using a metric ruler. The pencil has a known length of 14.2 cm. They record the following measurements: 13.7 cm, 13.6 cm, and 13.7 cm. What is the best way to describe their data?
a. Accurate, but not precise
c. BOTH accurate and precise
b. Precise, but not accurate
d. NEITHER accurate nor precise
Answer:
Neither accurate not precise
Complete combustion of 8.60 g of a hydrocarbon produced 26.5 g of CO2 and 12.2 g of H2O. What is the empirical formula for the hydrocarbon?
The empirical formula of the hydrocarbon is [tex]C_2H_3[/tex] if combustion of 8.60 g of a hydrocarbon produced 26.5 g of [tex]CO_2[/tex] and 12.2 g of [tex]H_2O[/tex].
What is an empirical formula?A chemical formula showing the simplest ratio of elements in a compound rather than the total number of atoms in the molecule [tex]CH_2O[/tex] is the empirical formula for glucose.
1 mole of carbon dioxide contains a mass of 44 g, out of which 12 g are carbon.
Hence, in this case the mass of carbon in 8.46 g of [tex]CO_2[/tex]:
([tex]\frac{12}{44}[/tex]) × 8.46 = 2.3073 g
1 mole of water contains 18 g, out of which 2 g is hydrogen;
Therefore, 2.6 g of water contains;
([tex]\frac{2}{18}[/tex] × 2.6 = 0.2889 g of hydrogen.
Therefore, with the amount of carbon and hydrogen from the hydrocarbon, we can calculate the empirical formula.
We first calculate the number of moles of each,
Carbon = [tex]\frac{2.3073}{12}[/tex] = 0.1923 moles
Hydrogen = [tex]\frac{0.2889}{1}[/tex]= 0.2889 moles
Then, we calculate the ratio of Carbon to hydrogen by dividing by the smallest number value;
Carbon : Hydrogen
[tex]\frac{0.1923}{0.1923}[/tex] : [tex]\frac{0.2889}{0.1923}[/tex]
1 : 1.5
(1 : 1.5) 2
= 2 : 3
Hence, the empirical formula of the hydrocarbon is [tex]C_2H_3[/tex].
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Assume that you measured exactly 2.0 mL of the sodium chloride solution into a small test tube. How many moles of
sodium chloride are in the tube?
BaCl2(aq)+Na2SO4(aq)⟶BaSO4(s)+2NaCl(aq)
Using the balanced chemical equation, determine how many moles of NaCl will be produced, if 0.731 mol of BaCl2 is allowed to react with an excess of Na2SO4.
Answer:
1.46 moles NaCl
Explanation:
To find the moles of NaCl, you need to multiply the given value (0.731 moles BaCl₂) by the mole-to-mole ratio of the two relevant molecules. This ratio is made up of the coefficients in the balanced reaction. The numerator should contain moles NaCl to allow for the cancellation of moles BaCl₂. The final answer should have 3 sig figs to reflect the given value.
1 BaCl₂(aq) + Na₂SO₄(aq) ---> BaSO₄(s) + 2 NaCl(aq)
0.731 mole BaCl₂ 2 moles NaCl
--------------------------- x ------------------------- = 1.46 moles NaCl
1 mole BaCl₂
If 0.731 mol of BaCl₂ is allowed to react with an excess of Na₂SO₄, 1.462 moles of NaCl will be produced.
The balanced chemical equation is:
BaCl₂(aq) + Na₂SO₄(aq) → BaSO₄(s) + 2NaCl(aq)
The mole ratio of BaCl₂ to NaCl is 1:2. This means that 1 mole of BaCl2 will produce 2 moles of NaCl.
Moles of BaCl₂ = 0.731 mol
Mole ratio BaCl₂:NaCl = 1:2
Moles of NaCl = 0.731 mol * 2 = 1.462 mol
If we have 0.731 moles of BaCl₂, then we will produce 2 * 0.731 = 1.462 moles of NaCl.
Therefore, 1.462 moles of NaCl will be produced.
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among these properties of acids basses or both which property is specific to acids only? A. accepts protons B. bitter taste C. electricity conductive D. slippery feel
Answer:
C. electricity conductive
• How did your experimental absolute zero value compare to the accepted value?
The experimental absolute zero value is less when compared to the accepted value of absolute zero.
What is absolute zero?Absolute zero is defined as the temperature in which the lowest energy possible is attained in a thermodynamic system.
Absolute zero temperature has an accepted values of 0 Kelvin or -273.15 degrees Celsius.
At absolute zero, it is assumed that the volume of an ideal gas becomes zero. However, it has not been possible to cool any gas to absolute zero.
Based on the graph of temperature against volume of gases, the experimental absolute zero extrapolated from the graph where volume of the gases becomes zero is -285 degrees Celsius.
Therefore, the experimental absolute zero value is less when compared to the accepted value.
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Answer:
The experimental absolute zero value is less when compared to the accepted value of absolute zero.What is absolute zero?Absolute zero is defined as the temperature in which the lowest energy possible is attained in a thermodynamic system.Absolute zero temperature has an accepted values of 0 Kelvin or -273.15 degrees Celsius.At absolute zero, it is assumed that the volume of an ideal gas becomes zero. However, it has not been possible to cool any gas to absolute zero.Based on the graph of temperature against volume of gases, the experimental absolute zero extrapolated from the graph where volume of the gases becomes zero is -285 degrees Celsius.Therefore, the experimental absolute zero value is less when compared to the accepted value.
Explanation:
A metal object with mass of 22.7 g is heated to 97.0 ∘C and then transferred to an insulated container containing 84.7 g of water at 20.5 ∘C. The water temperature rises and the temperature of the metal object falls until they both reach the same final temperature of 24.3 ∘C. What is the specific heat of this metal object? Assume that all the heat lost by the metal object is absorbed by the water.
The specific heat of the metal object with a mass of 22.7g heated to to temperature of 97.0°C and then transferred to an insulated container containing 84.7 g of water at 20.5 ∘C is 0.815J/g°C
How to calculate specific heat?
The specific heat capacity of a metal can be calculated using the calorimetry equation as follows:
Q = mc∆T
Where;
Q = quantity of heat absorbed
m = mass of substance
c = specific heat capacity
∆T = change in temperature
mc∆T (water) = -mc∆T (metal)
84.7 × 4.18 × 3.8 = - (22.7 × c × -72.7)
1345.375 = 1650.29c
c = 0.815J/g°C
Therefore, the specific heat of the metal object with a mass of 22.7g heated to to temperature of 97.0°C and then transferred to an insulated container containing 84.7 g of water at 20.5 ∘C is 0.815J/g°C.
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Lisa made observations of stars at different times of the year. She noticed a lot of patterns in the fall, while she couldn't find any patterns in the summer. Why might this be?
This is because fall has more weather patterns which are repetitive than summer.
What is Weather?This is defined as the atmospheric condition of a particular place at a given period of time.
The repetitive weather patterns have various effects on the stars which is why they were studied.
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If the earth were the size of an apple, which piece would best represent the amount of mass of the
atmosphere?
O the skin
O the meat
O the stem
O Oops..... I am sorry. I just ate the Pacific Ocean by mistake.
O a seed
Enter the coefficient of C₂H6O that correctly balances the equation:
C₂H60+302 → 2CO2 + 3H₂O
Answer:
1 C₂H₆O
Explanation:
The given equation:
C₂H₆O + 3 O₂ ---> 2 CO₂ + 3 H₂O
Reactants: 2 carbon, 6 hydrogen, 7 oxygen
Products: 2 carbon, 6 hydrogen, 7 oxygen
As you can see, the amount of each element on both sides is identical. Therefore, the reaction is already balanced. This means that the coefficient in front of C₂H₆O is 1. When writing the equation, writing the one is insignificant and usually left out.
One donut contains 350 kcal. Convert this to calories and joules
350 Kcal is equals to 350000 calorie and 1464400 Joule.
How to calculate energy content in food ?The equation for calculating the energy content of a food source via calorimetry is as follows: Energy (joules) = Mass of water (g) × 4.2 (J/gºC) × Temperature increase (ºC)
1 Kcal = 1000 calorie
Therefore,
35 Kcal = 350 x 1000
= 350000 calorie
Now,
1 calorie = 4.184 joule
Therefore,
35000 calorie = 350000 x 4.184
= 1464400 joule
Hence, 350 Kcal is equals to 350000 calorie and 1464400 Joule.
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