Question

1) What is/are the spectator ion(s) for the following chemical reaction? Check all that apply.

Pb(NO3)2(aq) + Na2S(aq) --> PbS(s) + 2 NaNO3(aq)

a)

Pb2+ ion

b) Na+ ion

C) S2- ion

D)

NO3- ion

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Question 2

What is the driving force of reaction 4B?

Neutralization

Gas formation

Single displacement

Precipitation

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Question 3

Predict the products of the following reaction:

Mg(s) + HCl(aq) -->

MgCl2 and H2

MgH and Cl2

MgCl and H

MgCl2 and H+

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Question 4

NaClO is commonly used as bleach. The following is a sample reaction of NaClO. What is the oxidizing agent in this reaction?

3 NaClO + H2S --> 3 NaCl + H2O + SO2

NaCl

NaClO

H2S

SO2

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Question 5

When colorless Ba(NO3)2 solution mixes with colorless Na2SO4 solution:

The color of solution will change

Some bubbles will be produced

Nothing obvious will happen

A precipitate will form

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Question 6

A test tube has a colorless aqueous layer of NaI solution and an colorless organic layer of methylene chloride. When a few mL of colorless chlorine water is added to this test tube. The organic layer became pink. What is causing this pink color in the organic layer?

NaI

I2

NaCl

Cl2

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Question 7

Which of the following has the lowest concentration of H+?

They all have the same concentration of H+

0.1 mol HCl

0.1 mol HNO3

0.1 mol CH3COOH

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Question 8

What is the oxidation state of N in AgNO3?

+1

-1

-3

+3

+5

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Question 9

A water sample with unknown mass absorbed 100.0 J of heat and the temperature increased from 25.0 C to 29.8 C. What is the mass of this water sample? Specific heat of water = 4.184 J/(gC).

Note: To avoid any sig fig issues, please keep only two sig figs for your input!!

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Question 10

Which one is correct about the following process?

CH4 + 2 O2 --> CO2 + 2 H2O

It is endothermic with positive enthalpy change.

It is exothermic with positive enthalpy change.

It is exothermic with negative enthalpy change.

It is endothermic with negative enthalpy change.

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Question 11

100.0 mL of 1.00 mol/L NaOH reacted with 65.4 mL of 1.00 mol/L CH3COOH solution and the temperature increased from 20 to 22 C. How many moles of NaOH get and CH3COOH are neutralized?

Note: to avoid any sig fig issues, please use regular decimal instead of scientific notation and keep 3 sig figs for your input!!

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Question 12

At room temperature, H2SO4 is dissolved in water and the solution is much hotter. So the dissolution of H2SO4

released some heat and has a negative enthalpy change

absorbed some heat and has a negative enthalpy change

absorbed some heat and has a positive enthalpy change

released some heat and has a positive enthalpy change

Answer 1

Question 1.

Pb(NO₃)_2(aq) + Na₂S_(aq) -------------> PbS_(s) + 2NaNO_3(aq)

Pb²⁺ + 2NO₃^- + 2Na⁺ + S^2- ------------> PbS_(s) + 2Na⁺ + 2NO₃^-

Pb²⁺ + S^2- -----------> PbS

The expected ions would be option a) and c)

Question 2: Please put the reaction 4B that it's mentioning here so I can Answer it.

Question 3: Mg_(s) + 2HCl_(aq) ------------> MgCl₂ + H₂

This is because this a reaction where an atom (Mg) displaces the atom of H. The reaction that is taking place is a single desplacement.

Question 4: 3NaClO + H₂S --> 3NaCl + H₂O + SO₂

If you calculate the valence of NaClO:

-2x1 + X + 1 = 0

X = +1

In the NaCl, has a valence of -1 (Because Sodium is still +1), so it's passing from +1 to -1, this mean that is reducting. If this atom is being reducted, means that the S is oxidating, as you can see here:

SO₂ ----> -2x2 + X = 0 ----> X = +4; H₂S = 2x1 + X = 0 ----> X = -2

It's passing from -2to +4, so it's oxidating as I said. This mean that if NaClO is being reducted, then the NaClO is the oxidating agent, and the H₂S is the reductor agent. The correct answer would be NaClO is the oxidating agent.

Question 5. The overall reaction: Ba(NO₃)₂ + Na₂SO₄ --------> BaSO₄ + 2NaNO₃

This kind of reaction, it's a double desplacement reaction. In both colorless compound, the solution will remain the same. And they are both salts, so, in this condition, the reaction will form a precipitade.

Question 7.

HCl and HNO₃ they are both strong acids with a dissociation constant really low. So the dissociation of H⁺ on both acids would be the complete and the same, so [HNO₃] = [H⁺] same thing happen with HCl. But the CH₃COOH is a weak acid, and has a Ka. So the dissociation would have a lower [H] than the innitial. So the answer would be CH₃COOH has the lower [H⁺] concentration.

Question 8.

AgNO₃ ----> If Ag = 1+ and O = 2- then:+

(-2x3) + X + 1 = 0

-6+1+X = 0

X = +5

The oxidation state of N would be +5

For the rest of your questions, I would love to answer all of them, but please post all of them in a new question per separate, so you can get a better and faster answer. Anything else, you can tell me in a comment.