Question 1

A sample of water is heated from $25\ ^\circ\mathrm{C}$ to $100\ ^\circ\mathrm{C}$. What is the temperature change in Kelvin ($K$)?

Accepted Answer

$75\ K$

Question 2

Which of the following numbers is correctly written in standard scientific notation?

Accepted Answer

$4.5 	imes 10^{2}$

Question 3

How many significant figures are in the measurement $0.004560$?

Accepted Answer

4

Question 4

Convert $0.0035$ grams to micrograms ($\mu g$).

Accepted Answer

$3,500\ \mu g$

Question 5

A block has a mass of $250\ g$ and a volume of $50.0\ cm^3$. What is its density?

Accepted Answer

$5.00\ g/cm^3$

Question 6

An atom of magnesium has an atomic number of $12$ and a mass number of $25$. How many neutrons does it have?

Accepted Answer

$13$

Question 7

Which of the following sets contains only nonmetals?

Accepted Answer

Oxygen, Nitrogen, Sulfur

Question 8

What is the correct formula and name for the polyatomic ion with a $-3$ charge and containing phosphorus and oxygen?

Accepted Answer

$\mathrm{PO}_4^{3-}$, phosphate

Question 9

What is the correct name for $\mathrm{FeCl}_3$?

Accepted Answer

Iron(III) chloride

Question 10

Which of the following is a synthesis reaction?

Accepted Answer

$2\mathrm{H}_2 + \mathrm{O}_2 \rightarrow 2\mathrm{H}_2\mathrm{O}$

Question 11

Calculate the molar mass of $\mathrm{Ca(NO}_3)_2$.

Accepted Answer

$164\ g/mol$

Question 12

How many molecules are in $18.0\ g$ of water ($\mathrm{H}_2\mathrm{O}$)? ($M_{\mathrm{H}_2\mathrm{O}} = 18.0\ g/mol$)

Accepted Answer

$6.02 	imes 10^{23}$

Question 13

A reaction has a theoretical yield of $10.0\ g$ but only $7.5\ g$ of product is actually obtained. What is the percent yield?

Accepted Answer

$75\%$

Question 14

Which of the following is a chemical change?

Accepted Answer

Rusting of iron

Question 15

How many oxygen atoms are in one formula unit of $\mathrm{Al}_2(\mathrm{SO}_4)_3$?

Accepted Answer

12

Question 16

A student mixes $10.0\ g$ of $\mathrm{NaCl}$ with $10.0\ g$ of $\mathrm{AgNO}_3$ in water. The balanced equation is $\mathrm{NaCl} + \mathrm{AgNO}_3 \rightarrow \mathrm{AgCl} + \mathrm{NaNO}_3$. Which reactant is the limiting reagent? ($M_{\mathrm{NaCl}} = 58.5\ g/mol$, $M_{\mathrm{AgNO}_3} = 170\ g/mol$)

Accepted Answer

$\mathrm{NaCl}$

Question 17

Which of the following is the correct name for $\mathrm{N}_2\mathrm{O}_5$?

Accepted Answer

Dinitrogen pentoxide

Question 18

Which of the following is the correct formula for phosphoric acid?

Accepted Answer

$\mathrm{H}_3\mathrm{PO}_4$

Question 19

A sample contains $2.0 	imes 10^{24}$ molecules of $\mathrm{CO}_2$. How many moles of $\mathrm{CO}_2$ are present?

Accepted Answer

$3.32\ 	ext{mol}$

Question 20

Which of the following is a double replacement reaction?

Accepted Answer

$\mathrm{AgNO}_3 + \mathrm{NaCl} \rightarrow \mathrm{AgCl} + \mathrm{NaNO}_3$

CHEM 151 Exam 1 Study Guide: Essential Concepts and Skills

Study Guide - Practice Questions

Study Guide - Flashcards