Answer: A homogeneous mixture has the same uniform appearance and composition throughout. Many homogeneous mixtures are commonly referred to as solutions. A heterogeneous mixture consists of visibly different substances or phases. ... Solutions have particles which are the size of atoms or molecules - too small to be seen.
The pH of a solution after a base and an acid have neutralized each other is ___.
Group of answer choices
A) 6
B) 8
C) 7
D) 0
Answer: B
Explanation:
You are given 10.00 mL of a solution of an unknown acid. The pH of this solution is exactly 4.08. You determine that the concentration of the unknown acid was 0.3250 M. You also determined that the acid was monoprotic (HA). What is the pKa of your unknown acid
Answer:
Explanation:
pH = 4.08
[ H⁺ ] = 10⁻⁴°⁰⁸
= 8.3 x 10⁻⁵
concentration of acid = .3250 M
HA ⇆ H⁺ + A⁻
.325 8.3 x 10⁻⁵ 8.3 x 10⁻⁵
Ka = (8.3 x 10⁻⁵ )² / .325
= 68.9 x 10⁻¹⁰ / .325
= 212 x 10⁻¹⁰ M .
pKa = - log ( 212 x 10⁻¹⁰ )
= 10 - log 212
= 10 - 2.32
= 7.68 .
Which of the following is NOT an acceptable name for a vertical section of the periodic chart?
O Group
O Column
O Period
O Family
Answer:
Group
Explanation:
What influences electrical conductivity?
Answer:Electrical conductivity of earth materials is influenced by the metal content (sulfides) in the rock, porosity, clay content, permeability, and degree of pore saturation. hope this helps
Explanation:
NaBH4 is typically used in excess. Since the rate law for reduction of an aldehyde is first order in both NaBH4 and in aldehyde, how will using excess NaBH4 affect the overall reaction rate
Answer:
As the amount of NaBH4 is increased, the overall reaction rate also increases
Explanation:
This question tells us that NaBH4 is typically used in excess.
the rate law for reduction of an aldehyde is first order in NaBH4 and also in aldehyde,
We have The rate of reaction to be the equation below;
Rate = k[aldehyde][NaBH4]
The Rate of the reaction is directly proportional to NaBH4 concentration.
Therefore since they are directly proportional, when the amount of NaBH4 is increased, we will also have the overall reaction rate increase.
Ne belongs to what group. a. noble gases, b.alkali metals, c. halogens, d. alkaline earth metals
Which element is oxidized in the following reaction? Fe(s) + 2HCL(aq) -FeCL2(aq) + H2(g)
Which of the following pieces of technology expand the sense of sight?
Bubble A. microscopes and magnifying glasses
Bubble B. eyeglasses and contact lenses
Bubble C. binoculars and telescopes
Bubble D. all of these
Answer:
D
Explanation:
They make your sight better in your daily life and all of them are used in labs and other place's
what is a way that scientists communicate their
results to others?
HELP PLS!
Answer:
The main ways that scientists communicate research results is by publishing the results in journals. ... Some journals are peer-reviewed, meaning they only publish articles that pass a certain standard of quality -- peer-reviewed journals are usually for a specific audience, such as other scientists.
Explanation:
When 1.34 g Zn(s) reacts with 60.0 mL of 0.750 M HCl(aq), 3.14 kJ of heat are produced. Determine the enthalpy change per mole of zinc reacting for the reaction:
Answer:
Explanation:
Zn + 2HCl = ZnCl₂ + H₂
1 mole 2 mole
1.34 g = 1.34 / 65. = .0206 mole
60 mL of .75 M HCl = .045 mole of HCl
so full .0206 mole of Zn will react with .0412 mole of HCl
.0206 mole of Zn gives out 3.14 kJ of heat
1 mole of Zn will react to give 152.43 kJ of heat
enthalpy change of heat per mole of Zn
= 152.43 kJ .
What is the number of atoms in 2.65g of CH 4
Answer:
9.936x10^22 atoms of CH4
Explanation:
grams ----> mol
2.65 g CH4 if 1 mol of CH4 = 16.04 g CH4
2.65/16.04 = 0.165 mol of CH4
mol ------> atoms
1 mol = 6.022 x 10^23 atoms
0.165 mol x 6.022x10^23 = 9.936x10^22 atoms of CH4
When temperature drops, the number of collisions between particles increases
True?
False?
(1.6): What volume of oxygen, at 18°C and 750 torr, can be
obtained from heating 100gm of potassium chlorate, KCIO,?
Answer:
Volume of oxygen obtained = 30 L
Explanation:
Given data:
Mass of KClO₃ = 100 g
Pressure = 750 torr = 750/760 = 0.98 atm
Temperature = 18°C = 18+273 = 291 K
Volume of oxygen obtained = ?
Solution:
Chemical equation:
2KClO₃ → 3O₂ + 2KCl
Number of moles of KClO₃:
Number of moles = mass/molar mass
Number of moles = 100 g/ 122.55 g/mol
Number of moles = 0.82 mol
Now we will compare the moles of KClO₃ with oxygen.
KClO₃ : O₂
2 : 3
0.82 : 3/2×0.82 = 1.23 mol
Volume of oxygen:
PV = nRT
0.98 atm × V = 1.23 mol ×0.0821 atm.L/mol.K × 291 K
0.98 atm × V = 29.4 atm.L
V = 29.4 atm.L /0.98 atm
V = 30 L
A magnet can be used to.
Bubble A. attract metal objects
Bubble B. measure the length of an object
Bubble C. measure the temperature of an object
Bubble D. measure the mass of an object
Answer:
D.measure the mass of an object
Answer: a attract metal objects
Explanation:
are you slow this is the easiest thing ever
Insulin is a protein that is used by the body to regulate both carbohydrate and fat metabolism. A bottle contains 125 mL of insulin at a concentration of 50.0 mg/mL . What is the total mass of insulin in the bottle?
Answer:
the total mass of insulin in the bottle would be 3.75 g
hope this helps :)
Explanation:
c= 50 mg/mL
m = ?
v = 125 mL
c=m/v
[tex]\frac{50mg}{mL}[/tex]=[tex]\frac{m}{125mL}[/tex]
m=30×125
m=3750 mg or 3.75 g
Insulin has been the peptide hormone that is produced by the pancreatic cell of the body. The insulin solution of a concentration of 50 mg/ml has a mass of 6.25 grams.
What is insulin?Insulin has been the protein that is crucial for cell activity and function. It is a hormone that regulates the blood glucose level in a diabetic patient. The beta cell of the islets of the Langerhans of the pancreas makes insulin.
The glucose formed from the breaking of carbohydrates is controlled in the blood by insulin production so that the metabolic process can take place in an orderly manner.
Given,
Concentration of insulin hormone = 50 mg/mL
The volume of insulin in bottle = 125 mL
The mass of insulin can be calculated from the molar concentration and volume as:
Concentration = mass ÷ volume
Substituting the values above as:
50 mg/mL = mass ÷ 125 mL
Mass = 50 mg /mL × 125 mL
Mass = 6250 mg
The unit of mass is converted from milligram into gram as:
1 gm = 1000 mg
x gm = 6250 mg
x = 6.250 gm
Therefore, 50 gm/mL of concentration has 6.25 gm of insulin in it.
Learn more about insulin mass, here:
https://brainly.com/question/2800491
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How many moles of HCl needs to be added to a solution containing 0.10 mol of NH3 to make a buffer of pH 9.26
Answer:
The correct solution is "0.05 mol".
Explanation:
According to the question,
⇒ [tex]NH_{3}(aq)+HCL(aq)\rightarrow NH_{4}^+Cl^-(aq)[/tex]
0.10 x 0
(0.10-x) 0 x
Now,
[tex]pH=pKa+log\frac{[NH_{4}Cl]}{[NH_{3}]}[/tex]
[tex]9.26=9.26+log(\frac{x}{0.10-x} )[/tex]
[tex]log(\frac{x}{0.10-x})=0[/tex]
[tex]\frac{x}{0.10-x}=1[/tex]
[tex]2x=0.10[/tex]
[tex]x=0.05[/tex] (moles of HCL needed)
Susan has just moved into a new house. For some reason, she cannot get the grass to grow in her yard. She decided to grow small amounts of grass inside her house as part of an experiment. The first group of grass is exposed to light intensity of 400. The second group is exposed to light intensity of 1200. The graph below shows the results of Susan's experiment. 11. According to the graph, which of the following should be expected from Susan's two groups of plants?
A. The plants at a light intensity of 1200 will produce more oxygen than the plants at 400.
B. The plants at a light intensity of 1200 will perform only stage 1 of photosynthesis.
C. The plants at light intensity of 400 will produce more glucose than the plants at 1200.
D. The plants at a light intensity of 400 will grow more quickly than the plants at 1200.
Please help guys this is due tomorrow
Answer:
A
Explanation:
3. What is the mass of an object with a density of 1.7 g/cm3 and a volume of 7 cm3?
4. What is the mass of an object with a density of 0.9 g/mL and a volume of 10 mL?
5. What is the volume of a substance with a density of 0.87 g/mL and a mass of 14 g?
6. What is the volume of an object with a density of 2.3 g/mL and a mass of 24 g?
Answer:
all the answer in step are in picture
a) What mass of aluminium nitrate (Al(NO3)3) would be required to prepare 2.000 L of a 0.0170 M aqueous solution of this salt
Answer: 7.24 g of aluminium nitrate is required to prepare 2.000 L of a 0.0170 M aqueous solution of this salt.
Explanation:
Molarity of a solution is defined as the number of moles of solute dissolved per Liter of the solution.
Given :
Molarity of solution = 0.0170 M
Volume of solution = 2.000 L
[tex]Molarity=\frac{n}{V_s}[/tex]
where,
n= moles of solute
[tex]Moles=\frac{\text{Given mass}}{\text{Molar mass}}=\frac{xg}{213g/mol}[/tex]
[tex]V_s[/tex] = volume of solution in Liter = 2.000 L
[tex]0.0170M=\frac{x}{213g/mol\times 2.000L}[/tex]
[tex]x=7.24g[/tex]
7.24 g of aluminium nitrate is required to prepare 2.000 L of a 0.0170 M aqueous solution of this salt.
HELP ME PLEASE!!!! !!!!!!!!!!
In a certain chemical reaction Compound combines with Compound to produce Compound (and no other products). Measurements were taken of the amounts of and present before and after a reaction that produced some :
Answer:
2.1 g
Explanation:
The question is incomplete and the complete question is shown in the image attached to this answer.
Now look at that image closely; you will notice that:
i) Reactant A is the limiting reactant because it was used up in the reaction.
ii) Reactant B is the reactant in excess because some mass of it was left behind after the reaction.
The mass of the product C formed is the same as the mass of the limiting reactant used up. Hence the theoretical yield of C is 2.5 g
% yield = actual yield/theoretical yield * 100
since = 83%
Actual yield = %yield * theoretical yield/ 100
Actual yield = 83 * 2.5/100
Actual yield = 2.075 g
Calculate the pH of a 0.20 M NH3/0.20 M NH4Cl buffer after the addition of 15.0 mL of 0.10 M HCl to 65.0 mL of the buffer.
To what volume (in mL) would you need to dilute 40.0 mL of a 1.25 M solution of NaCl to make a 0.0500 M solution of NaCl
Answer:
1000 mL.
Explanation:
From the question given above, the following data were obtained:
Volume of stock solution (V1) = 40 mL
Molarity of stock solution (M1) = 1.25 M
Molarity of diluted solution (M2) = 0.05 M
Volume of diluted solution (V2) =...?
The volume of diluted solution can be obtained as shown below:
M1V1 = M1V1
1.25 × 40 = 0.05 × V2
50 = 0.05 × V2
Divide both side by 0.05
V2 = 50/0.05
V2 = 1000 mL
Therefore, the stock solution must be diluted to 1000 mL to obtain a 0.05 M solution of NaCl.
determine the empriical fornula of warfarin, a rodenticide which consists of 74.01% C, 5.23% H, and 20.76% o by mass
Answer:
Explanation:
C = 74.01 %
H= 5.23 %
O=20.76 %
Ratio of moles of C , H , O
= 74.01 / 12 : 5.23 / 1 : 20.76 / 16
= 6.1675 ;5.23 : 1.2975
= 4.75 : 4.03 : 1
= 4.75 / .25 : 4.03 / .25 : 1/.25
= 19 : 16 : 4
Empirical formula
= C₁₉ H₁₆O₄ .
Which elements are likely to be the Most reactive metals, based on the
number of valence electrons? Why?*
O Group 1/1A becuase it has one valence electron
O
Group 3/3A because it has both metals and metalloids
о
Group 17/7A because it has 7 Valence Electrons
Group 18/8A because it has 8 Valence Electrons
What atom has an atomic radius larger than iron? Cl Ca Se C
Answer:
Ca
Explanation:
Atomic radii vary in a predictable way across the periodic table. As can be seen in the figures below, the atomic radius increases from top to bottom in a group, and decreases from left to right across a period. Thus, helium is the smallest element, and francium is the largest.
For the reaction, Ni (s) and HCl (aq), write the molecular, complete ionic and net ionic equations. Note: most likely charge on the nickel cation is +2.
Answer:
Explanation:
Balanced Molecular reaction
[tex]Ni(s) + 2HCl(aq)[/tex] →[tex]NiCl2(aq) +H2(g)[/tex]
Complete ionic reaction
[tex]2 H^+ (aq) + 2 Cl^- (aq) + Ni (s)[/tex]→[tex]Ni^2+ (aq) + 2 Cl^- (aq) + H2 (g)[/tex]
Net ionic reaction
[tex]Ni(s)+ 2H^+(aq)[/tex]→[tex]Ni^2+(aq) + H2(g)[/tex]
What molecules frorn food and air end up in the cells in the body?
Rank the SN1 reaction rates for the following compounds: (A) chloromethane, (B) 3-chloro-3-methylpentane, (C) 1-chloro-3-methylpentane, (D) 2-chloro-3-methylpentane
Answer:
3-chloro-3-methylpentane,>2-chloro-3-methylpentane> 1-chloro-3-methylpentane, > chloromethane
Explanation:
The rate of SN1 reactions decreases in the order, tertiary > secondary > primary > methyl.
This implies that, a tertiary alkyl halide is better able to undergo nucleophilic substitution by SN1 mechanism compared to a secondary, primary or methyl.
This is because, the transition state leading to the formation of an SN1 product involves a carbocation. The order of stability of carbocations is; tertiary > secondary > primary > methyl.
Hence a tertiary alkyl halide such as 3-chloro-3-methylpentane leads to a more stable transition state and undergoes SN1 reaction at a faster rate.
All the elements beyond uranium, the transuranium elements, have been prepared by bombardment and are not naturally occurring elements. The first transuranium element neptunium, NpNp, was prepared by bombarding U−238U−238 with neutrons to form a neptunium atom and a beta particle. Part A Complete the following equation: 10n+23892U→?+?01n+92238U→?+? Express your answer as a nuclear equation.
Answer:
¹₀n+ ²³⁸₉₂U → ²³⁹₉₃Np + ⁰₋₁e
Explanation:
Key statement;
The first transuranium element neptunium, NpNp, was prepared by bombarding U−238U−238 with neutrons to form a neptunium atom and a beta particle.
This is the beta particle; ⁰₋₁e
¹₀n+ ²³⁸₉₂U → Np + ⁰₋₁e
The mass number of Np;
1 + 238 = Np + 0
Np = 239
The atomic number of Np;
0 + 92 = Np + (-1)
92 + 1 = Np
Np = 93
The equation is given as;
¹₀n+ ²³⁸₉₂U → ²³⁹₉₃Np + ⁰₋₁e