Answer:
It has 17 protons, 17 electrons, and 18 neutrons/ 35 protons, 35 electrons, and 17 neutrons. 21. Phosphorus-33 (atomic number 15) contains 18 neutrons/ 18 protons
Why does the liquid in a thermometer go down when it is placed in ice water?
The cold of the ice makes the liquid condense?
The surrounding air is too hot?
The density is decreasing with the temperature?
The liquid is attracted to the cold?
Answer: A) Cold ice makes the liquid condense
On the flip side, warm temperatures make the liquid expand. Since there is only one direction to go, the liquid expands upward until it reaches a certain marker on the thermometer, to indicate the temperature.
How is mechanical weathering different from chemical weathering?
a
Chemical weathering happens over a much shorter time frame than mechanical weathering.
b
Chemical weathering happens in the tropics; mechanical weathering occurs in temperate climates.
c
Chemical weathering happens in mountains; mechanical weathering happens on flat surfaces.
d
Chemical weathering changes the chemical makeup of materials; mechanical weathering doesn't.
Answer:
c
Explanation:
classify the following mixtures as to its type: (solution/colloid/suspension)
a. condensed milk-
b. paint-
c. flour and water-
d. brine (salty water)-
Answer:
Colloid = Condensed milk, Paint
Solution = brine
Suspension = flour and water
Explanation:
Colloid:
Colloid is a mixture in which smaller particles of one substance are evenly distributed throughout into another substance.
These particles are smaller than the particles present in suspension but larger than the particles present in solution.
Condensed milk is example of colloid.
Paint is also example of colloid in which pigment particles dispersed.
Solution:
In solution one or more substances are dissolved into the another substance. The substance which is being dissolved is called solute while the substance which has tendency to dissolve the other substance is called solvent. It is homogenous mixture.
Salty water is example of solution in which salt are solute dissolved in solvent which is water.
Suspension:
In suspension solute particles are not dissolved they are dispersed into bulk of solvent. The solute particles are larger then the particles present in colloid.
flour and water is the example of suspension.
How many molecules of water are produced when 8.93 * 1023 molecules of oxygen are reacted with
excess hydrogen gas in the reaction below?
2H2 + O2 → 2H2O
Answer: 1.79 x 10^24 molecules H2O
Explanation:
Use the following conversion factors to convert from molecules of oxygen to molecules of water: 1 mole O2/ 6.02 x 10^23 molecules O2, 2 mole H2O/ 1 mole O2, 6.02 x 10^23 molecules H2O/ 1 moles H2O
will gave a brain thingy. What are the conditions required for natural selection? Check all that apply.
overproduction of offspring
same traits among all organisms in a population
variation among organisms in a population
favorable adaptations selected by nature
unfavorable adaptations passed on to offspring in larger numbers
favorable adaptations building in population over time
Answer:
everything.
Explanation:
You need nice weather,good realation ships as well as convection
Answer:
A C D F
Explanation:
Proper way water molecules form hydrogen bonds
Explanation:
Water molecules form hydrogen bonding when the oxygen of one water molecule combines with the hydrogen of another molecule.
Hydrogen bonding is an electrostatic attraction between the hydrogen atom of one molecule and the electronegative atom of a neighboring molecule.
This bond is made possible by the electronegativity difference between oxygen and hydrogen for water molecules. The intermolecular forces is responsible for the physical and chemical properties of water.What are the BCNOs in relation to the periodic table?
Answer:
Binding properties
Explanation:
g what is ΔG for the reaction at 298K, when the partial pressure of C2H4 is 0.275 atm, the partial pressure of H2O is 0.350 atm, and the partial pressure of C2H5OH is 0.100 atm?
Answer:
[tex]\Delta G=8015\frac{J}{mol}[/tex]
Explanation:
Hello.
In this case, for the following chemical reaction in gaseous phase:
[tex]C_2H_4+H_2O\rightleftharpoons C_2H_5OH[/tex]
We can write the equilibrium expression as:
[tex]Kp=\frac{p_{C_2H_5OH}}{p_{H_2O}*p_{C_2H_4}}[/tex]
it means that given the pressures, we can compute Kp as shown below:
[tex]Kp=\frac{0.100atm}{0.275atm*0.350atm}=1.04[/tex]
Next, we compute Kc at 298 K:
[tex]Kc=\frac{Kp}{(RT)^{1-1-1}}=\frac{Kp}{(RT)^{-1}}[/tex]
Whereas 1-1-1 comes from the stoichiometric coefficients of products minus reactants. Therefore, Kc is:
[tex]Kc=\frac{1.04}{(0.08206*298)^{-1}}=25.4[/tex]
Thus, the Gibbs free energy for this reaction is:
[tex]\Delta G=RTln(kC)=8.314\frac{J}{mol*K}*298K*ln(25.4)\\ \\\Delta G=8015\frac{J}{mol}[/tex]
Best regards!
A flask contains 15.5mL of hydrogen that was collected under a pressure of
22.5 kPa. What pressure would have been required for the volume of the gas
to have been 9.00mL, assuming the same temperature?*
the chemical formula of tetraphosphorus hexasulfide
Answer:
Molecular Formula
P4S6
Molecular Weight
316.3 g/mol
P[tex]_4[/tex]S[tex]_6[/tex] is the chemical formula of tetraphosphorus hexasulfide. These can only include one typographic line containing symbols.
A chemical formula is a way to describe the chemical ratios of the atoms that make up a specific chemical compound or molecule in chemistry. Chemical element numbers, symbols, and on occasion other symbols, including parentheses, dashes, brackets, commas, and plus (+) and minus () signs, are used to represent the chemical elements. Which may also include subscripts or superscripts. Since a chemical formula inherently wordless, it cannot be considered a chemical name. A chemical formula does not equal a complete chemical structural formula, despite the fact that it may suggest certain basic chemical structures. P[tex]_4[/tex]S[tex]_6[/tex] is the chemical formula of tetraphosphorus hexasulfide.
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A 125-mL sample of gas at 105 kPa has its volume reduced to 75.0 mL. What is the new pressure?
Answer:
87.0
Explanation:
Hopes this helps
2. Glucose, C6H12O6, along with O2 is a product that is produced from photosynthesis of plants. How many grams of carbon are in 16.55 g of glucose
Answer:
6.62 g of carbon.
Explanation:
We'll begin by calculating the molar mass of C6H12O6. This is illustrated below:
Molar mass of C6H12O6 = (12×6) + (12×1) + (16×6)
= 72 + 12 + 96
= 180 g/mol
Next, we shall determine the mass of carbon (C) in 1 mole (i.e 180 g) of C6H12O6. This is illustrated:
Mass of C in C6H12O6 = 6C = 12×6
Mass of C in C6H12O6 = 72 g
Thus, 180 g of glucose contains 72 g of carbon.
Finally, we shall determine the mass of carbon in 16.55 g of glucose. This can be obtained as follow:
180 g of glucose contains 72 g of carbon.
Therefore, 16.55 g of glucose will contain = (16.55 × 72)/180 = 6.62 g of carbon.
Thus, 16.55 g of glucose contains 6.62 g of carbon.
Do not look up the answer on google, because I know exactly what the answer is. If you answer right will give thanks and brainliest
Answer:
THE ANSWER IS CORRECT!!
AgCL would be least soulble at 25 degrees Celcius in ___ A. pure water B. 0.1 M HNO3 C. 0.1 M CaCl2 D. 0.1 M HCL E. It is equally soluble in all of these substances.
Answer: The answer is C. 0.1MCaCl2
Explanation:
We have AgCl whose least solubility is to be determined at 25degree Celsius
so upon looking at the options given we observe C 0.1MCaCl2 and D 0.1MHCl both have chlorine ions present and we know that here common ion effect will happen that causes decreases the solubility of the AgCl here
but when Calcium chloride dissociates it gives 2 moles of chlorine ions
[tex]CaCl2[/tex]→[tex]Ca^+2 + 2Cl^-[/tex]
so chlorine ion will be present in more amount [tex]2*0.1\\[/tex]=[tex]0.2[/tex] as compared to the chlorine produced by HCl
[tex]HCl[/tex]→[tex]H^+ +Cl^-[/tex] only 1 mole of chlorine is produced.
Hence AgCl will be least soluble in 0.1M CaCl2
Which of these is measured during a scientific investigation
Answer:
What ae the options?
Explanation:
PLEASE HELP ME!!!
Which of these is measured during a scientific investigation?
Group of answer choices
Test variable (independent variable)
Outcome variable (dependent variable)
Control group
Hypothesis
Answer:
Outcome Variable
Explanation:
Control group and Hypothesis are not what your measuring.
Test variable would be like- "amount of water added"
Outcome variable would be something like- "amount plants grew"
You would be measuring the amounts the plants grew, based on the water added.
if the rate of appearance of no2 is equal to 8.00mol/min at a particular moment, what is the rate of dissapearce of N2O5 at that moment
Answer:
[tex]r_{N_2O_5}=-4.00mol/min\[/tex]
Explanation:
Hello.
In this case, since the chemical reaction is:
[tex]2N_2O_5\rightarrow 4NO_2+O_2[/tex]
We can write the rate ratio between N2O5 and NO2 as shown below:
[tex]\frac{1}{-2} r_{N_2O_5}= \frac{1}{4} r_{NO_2}[/tex]
Since N2O5 is consumed and NO2 produced at a rate of 8.00 mol/s, therefore, the rate of disappearance is N2O5 is:
[tex]r_{N_2O_5}= \frac{-2}{4} r_{NO_2}\\\\ r_{N_2O_5}=\frac{-1}{2} *8.00 mol/min\\\\ r_{N_2O_5}=-4.00mol/min[/tex]
Which is negative since N2O5 is a reactant.
Best regards!
Find the volume in liters of 2.00 * 10 ^ 23 molecules of F2 at STP?
Chromium (III) oxide reacts with hydrogen sulfide gas to form chromium (III) sulfide and water.a)writedown the balanced equation for the reaction.b)To produce 421 g of Cr2S3, how many moles of Cr2O3are required
Answer:
The balanced chemical equation for the reaction can be computed as:
[tex]\mathbf{Cr_2O_3_{(s)}+ 3H_2S_{(g)} \to Cr_2S_3_{(s)} + 3H_2O_{(l)}}[/tex]
2.103 moles of [tex]Cr_2O_3_{(s)}[/tex] is being required.
Explanation:
The balanced chemical equation for the reaction can be computed as:
[tex]\mathbf{Cr_2O_3_{(s)}+ 3H_2S_{(g)} \to Cr_2S_3_{(s)} + 3H_2O_{(l)}}[/tex]
Recall that numbers of moles = [tex]\dfrac{mass}{molar \ mass}[/tex]
∴
number of moles of Cr2S3 = [tex]\dfrac{421}{200.19}[/tex]
number of moles of Cr2S3 = 2.103 moles
It obvious from the balanced equation that:
1 mole of [tex]Cr_2S_3_{(s)}[/tex] requires 1 mole of [tex]Cr_2O_3_{(s)}[/tex]
Thus; 2.103 moles of [tex]Cr_2S_3_{(s)}[/tex] = 2.103 × (1/1) moles of [tex]Cr_2O_3_{(s)}[/tex]
= 2.103 moles of [tex]Cr_2O_3_{(s)}[/tex]
HELP, ONLY ONE ANSWER!
Which is a possible consequence of decreasing air quality resulting from global warming?
A.) drying out of fertile lands
B.) flooding of low-lying coastal areas
C.) melting of glaciers and polar ice caps
D.) decrease in population due to health threats
Answer:
Its d
Explanation:
Got it correct
Answer:
d
Explanation:
did the test
Liquid octane reacts with gaseous oxygen gas to produce gaseous carbon dioxide and gaseous water . If of carbon dioxide is produced from the reaction of of octane and of oxygen gas, calculate the percent yield of carbon dioxide. Be sure your answer has the correct number of significant digits in it.
The question is incomplete; the complete question is;
Liquid octane CH3CH26CH3 reacts with gaseous oxygen gas O2 to produce gaseous carbon dioxide CO2 and gaseous water H2O. If 2.80g of carbon dioxide is produced from the reaction of 3.4g of octane and 5.9g of oxygen gas, calculate the percent yield of carbon dioxide. Be sure your answer has the correct number of significant digits in it.
Answer:
55%
Explanation:
The balanced equation is:
C8H18(g) + 25/2O2(g) ----------> 8CO2(g) + 9H2O(g)
The limiting reactant IS first determined. This is the reactant that yields the least amount of product.
3.4 g octane / 114 g/mol = 0.030 mol octane
From the reaction equation;
1 mole of octane yields 8 moles of CO2
0.030 mol octane yields 0.030 * 8/1 = 0.24 moles of CO2
5.9 g O2 / 32 g/mol = 0.18 mol O2
25/2 moles of O2 yields 8 moles of CO2
0.18 moles of O2 yields 8 * 0.18/25/2 = 0.1152 moles of CO2
Oxygen is the limiting reactant.
Number of moles of carbon dioxide produced (actual yield) = 2.8 g/44g/mol = 0.0636 moles of CO2
% yield = actual yield/ theoretical yield * 100
% yield = 0.0636/0.1152 * 100= 55%
the reaction A->B is second order in A and the rate constant is 0.039L/mol s. if it took 23 sec for the concentration of A to decrease to 0.30 M, what was the starting concentration of A
Answer:
0.41 M
Explanation:
A -> B
rate constant (k) = 0.039L/mol s
t = 23
Final concentration, [A] = 0.30M
Initial concentration, [A]o = x
1 / [A] = kt + 1 / [A]o
1 / [A]o = 1 / [A] - kt
1 / [A]o = 1 / 0.30 - 0.039 (23)
1 / [A] = 3.33 - 0.897 = 2.433
[A] = 0.41 M
how can you determaine that a coin is not pure silver if you know the mass and volume of the coin plz hurry
Answer:
easy
Explanation:
Divide the mass by the volume to calculate its density. If its density isn't the same as an equal amount of pure silver, the coin has some other metal in it.
A sample of an ideal gas has a volume of 2.29 L at 285 K and 1.12 atm. Calculate the pressure when the volume is 1.33 L and the temperature is 302 K.
Answer:
[tex]P_2=2.04atm[/tex]
Explanation:
Hello.
In this case, by using the combined ideal gas law, we can identify the change in pressure, temperature an volume as shown below:
[tex]\frac{P_1V_1}{T_1} =\frac{P_2V_2}{T_2}[/tex]
In such a way, since we are asked to compute the final pressure, P2, we proceed as follows:
[tex]P_2=\frac{P_1V_1T_2}{T_1V_2} \\\\P_2=\frac{1.12atm*2.29L*302K}{285K*1.33L}\\ \\P_2=2.04atm[/tex]
Best regards!
How many moles of iron are needed to react with 0.125 moles of oxygen
Given; 4Fe + 3O2 = 2Fe2O3
Answer:
0.167 mol Fe
Explanation:
4 Fe + 3 O₂ ⇒ 2 Fe₂O₃
Convert moles of oxygen to moles of iron using the mole ratio. You can find the mole ratio using the chemical equation. For every 4 moles of iron, you will need 3 moles of oxygen.
(0.125 mol O₂) (4 mol Fe/3 mol O₂) = 0.167 mol Fe
Answer:
Your mom says to stop cheating
Explanation:
The current, most modern view of the atom is the ___
model.
A. Rutherford
B. quantum mechanical
C. Bohr
D. Thomson
E. Einstein
A 50.0 mL sample of 0.0152 M Na2SO4(aq)is added to 50.0 mL 0.0125 M Ca(NO3)2(aq). What percentage of the Ca2 remains unprecipitated
Answer:
38.4%
Explanation:
Step 1 Obtain the concentration of Ca^2+ and SO4^2-
[Ca^2+] = 0.05 L (0.0125 mol/L) (1/0.1 L) = 6.25 * 10^-3 M
[SO4^2-] = 0.05 L (0.0152mol/L) (1/0.1L) = 7.60 * 10^-3 M
Step 2 Obtain the concentration of [SO4^2-] left
Ca^2+(aq) + SO4^2-(aq)------> CaSO4(s)
initial 6.25 * 10^-3 M 7.60 * 10^-3 M
final 0 1.35 * 10^-3 M
Step 3 Determine the amount of Ca^2+ left from the common ion problem
CaSO4(s) --------> Ca^2+(aq) + SO4^2-(aq)
initial 0 1.35 * 10^-3 M
equilibrium x (1.35 * 10^-3 + x) M
But Ksp of CaSO4 = 9.1 * 10^-6
Ksp = [Ca^2+] [SO4^2-]
9.1 * 10^-6= [x] [1.35 * 10^-3 + x]
9.1 * 10^-6= 1.35 * 10^-3 x + x^2
Rearranging:
x^2 + 1.35 * 10^-3 x + 9.1 * 10^-6 = 0
solving the quadratic yields x = 2.4 * 10^-3
Step 4 Calculate the amount of Ca^2+ remaining;
% Ca^2+ remaining = 2.4 * 10^-3/ 6.25 * 10^-3 M * 100
% Ca^2+ remaining = 38.4%
Give the complete ionic equation for the reaction that occurs when aqueous solutions of sodium sulfide and iron(II) nitrate are mixed.
Answer:
2 Na⁺(aq) + S²⁻(aq) + Fe²⁺(aq) + 2 NO₃⁻(aq) ⇒ FeS(s) + 2 Na⁺(aq) + 2 NO₃⁻(aq)
Explanation:
Let's consider the molecular equation that occurs when aqueous solutions of sodium sulfide and iron(II) nitrate are mixed.
Na₂S(aq) + Fe(NO₃)₂ ⇒ FeS(s) + 2 NaNO₃(aq)
The complete ionic equation includes all the ions and the species that do not dissociate in water.
2 Na⁺(aq) + S²⁻(aq) + Fe²⁺(aq) + 2 NO₃⁻(aq) ⇒ FeS(s) + 2 Na⁺(aq) + 2 NO₃⁻(aq)
The complete ionic equation for the reaction between aqueous solution of sodium sulfide and iron(II) nitrate is
2Na⁺(aq) + S²⁻(aq) + Fe²⁺(aq) + 2NO₃⁻(aq) —> FeS(s) + 2Na⁺(aq) + 2NO₃⁻(aq)
The complete ionic equation for the reaction between aqueous solution of sodium sulfide and iron(II) nitrate can be written as follow:
In solution, Na₂S and Fe(NO₃)₂ will dissociate as follow:
Na₂S(aq) —> 2Na⁺(aq) + S²¯(aq)
Fe(NO₃)₂(aq) —> Fe²⁺(aq) + 2NO₃¯(aq)
The reaction will proceeds as illustrated below to give the complete ionic equation:
Na₂S(aq) + Fe(NO₃)₂(aq)—>
2Na⁺(aq) + S²¯(aq) + Fe²⁺(aq) + 2NO₃¯(aq) —> FeS(s) + 2Na⁺(aq) + 2NO₃¯(aq)
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The following reaction is a single replacement reaction. What happens to the oxidation number of the elements in this reaction? Show proof. Li(s) + CuCl2(s)=LiCl(s) + Cu(s)
Answer:
1. The oxidation number of Li changes from 0 to +1
2. The oxidation number of Cu changes from +2 to 0.
3. The oxidation number of Cl remains the same in each compound.
Explanation:the equation for the reaction is given below:
Li(s) + CuCl2(s) —> LiCl(s) + Cu(s)
Next, we shall determine the oxidation number of each element in the reaction.
NOTE: 1. Oxidation number of chlorine (Cl) is always –1 in any compound because it is a ground 7 element.
Now, we shall determine the change in oxidation number of each element. This is illustrated below:
1. For Li:
Li = 0 (ground state)
LiCl = 0
Cl = –1
Li + (–1) = 0
Li – 1 = 0
Collect like terms:
Li = 0 + 1
Li = +1
The oxidation number of Li changes from 0 to +1
2. For Cu:
CuCl2 = 0
Cu + 2Cl = 0
Cl = –1
Cu + 2(–1) = 0
Cu – 2 = 0
Collect like terms
Cu = 0 + 2
Cu = +2
Cu = 0 (ground state)
The oxidation number of Cu changes from +2 to 0.
3. For Cl:
The oxidation number of Cl remains the same in each compound.
Summary:
1. The oxidation number of Li changes from 0 to +1
2. The oxidation number of Cu changes from +2 to 0.
3. The oxidation number of Cl remains the same in each compound
1. How do scientists know how hot the
core is?
A. Thermometers
Seismic waves
C. Oil wells
D. Measure the electromagnetic
spectrum
A.THERMOMETERS SEISMIC WAVES