Question 1

Which of the following best describes a homogeneous mixture?

Accepted Answer

Salt water

Question 2

Which statement about compounds is correct?

Accepted Answer

Compounds contain two or more elements chemically combined in fixed ratios.

Question 3

Which of the following is a chemical change?

Accepted Answer

Burning a candle

Question 4

How many significant figures are in the measurement 0.005087?

Accepted Answer

4

Question 5

Which of the following is an example of a pure substance?

Accepted Answer

Oxygen

Question 6

What is the correct balanced chemical equation for the reaction of zinc with hydrochloric acid?

Accepted Answer

$$ \mathrm{Zn} + 2\mathrm{HCl} \rightarrow \mathrm{ZnCl}_2 + \mathrm{H}_2 $$

Question 7

Which of the following measurements is the most precise?

Accepted Answer

5.179 meters

Question 8

A student measures the mass of a sample three times and gets values close to each other but far from the true value. This is an example of:

Accepted Answer

Low accuracy, high precision

Question 9

Which of the following is the correct way to write 0.00052 in scientific notation?

Accepted Answer

$$ 5.2 	imes 10$$^{-4}$$ $$

Question 10

Which of the following is NOT a physical property?

Accepted Answer

Ability to rust

Question 11

How many atoms are present in one formula unit of $$ \mathrm{CaSO}_4 $$?

Accepted Answer

6

Question 12

Which of the following is a correct statement about elements and compounds?

Accepted Answer

Compounds can be separated into their elements by chemical means.

Question 13

Which of the following numbers has three significant figures?

Accepted Answer

1.11

Question 14

A chemical equation must be balanced to obey which law?

Accepted Answer

Law of Conservation of Mass

Question 15

Which of the following is a heterogeneous mixture?

Accepted Answer

Vegetable soup

Question 16

Which of the following is the correct answer to $$ 17.8 + 1.3421 $$ expressed with the correct number of significant figures?

Accepted Answer

$$ 19.1 $$

Question 17

Which of the following is a correct statement about the periodic table?

Accepted Answer

Groups are vertical columns of elements.

Question 18

Which of the following is an exact number?

Accepted Answer

1 dozen

Question 19

Which of the following is the correct answer to $$ \frac{4.98 + 3.38}{2.6} $$ expressed with the correct number of significant figures?

Accepted Answer

$$ 3.2 $$

Question 20

Which of the following best describes the difference between precision and accuracy?

Accepted Answer

Precision is how close measurements are to each other; accuracy is how close measurements are to the true value.

Matter and Measurement: Foundations of GOB Chemistry

Guida di studio - Domande di pratica