Unit 3 Exam

Last updated over 3 years ago
16 questions
2

What is an example of a chemical reaction?

2

A balanced chemical equation reflects that idea that the mass of the products..

2

2 Na (s) + Cl2 (g) --> 2 NaCl (s)

This equations represents a chemical change because...

2

What is the correct description of this reaction?

Zn (s) + 2HCl (aq) --> ZnCl2 (aq) + H2 (g)

2

Does the chemical equation below demonstrate the law of conservation of mass?
CH4 (g) + 2O2 (g) --> CO2 (g) + 2H2O (l)

2

Which of the following images represents the law of conservation of mass?

2

Which of the following equations represents the law of conservation of mass?

2

A student heated a 10 g sample of a compound in an open container. A chemical reaction occurred. The mass of the sample was measured again and found to be less than before. Which of the following explains the change in mass of the sample?

2

A 1.0- mole sample of carbon dioxide (CO2) gas has a mass of about...

2

According to the balanced chemical reaction below, a 1000 gram sample of NaCl (l) completely reacts, producing 400 grams of Na (l). What is the total mass of Cl2 (g) produced?

Hint: The law of conservation of mass states that mass can not be created or destroyed therefore the mass of the products must equal the mass of the reactants.

2NaCl (l) --> 2Na (l) + Cl2 (g)

2

“Hand Blasters” is a toy that consists of a set of two ceramic balls, each coated with a mixture of sulfur and potassium chlorate, KClO3. When the two balls are struck together, a loud popping noise is produced as sulfur and potassium chlorate react with each other. Balance the equation of this reaction below.

You must show your work for full credit.

2

A single-replacement reaction occurs when fluorine gas is bubbled through a solution of sodium iodide, as seen below.

NaI (aq) + F2 (g) --> NaF (aq) + I2 (s)

What is one piece of evidence that a chemical reaction between NaI and F2 has taken place?

2

A single-replacement reaction occurs when fluorine gas is bubbled through a solution of sodium iodide, as seen below.

NaI (aq) + F2 (g) --> NaF (aq) + I2 (s)

Balance the equation below. Be sure to show your work.

2

One way to produce table salt (NaCl) is to combine calcium chloride with solid sodium, according to the unbalanced reaction below.
Na + CaCl2 --> Ca + NaCl

Balance the equation that represents this process. Show all work.

2

Given the balanced equation representing a reaction: 4NH3 + 5O2 --> 4NO + 6H2O

What is the minimum number of moles of O2 that are needed to completely react with 16 moles of NH3?

Use dimensional analysis and mole ratios to answer the question above. Show all work below.

0

Bonus Question: Which comedian does Mr. De La Cruz wants to become like?