Question 1

A mixture of sand and salt can be separated by which type of process, and what does this indicate about the nature of mixtures?

Accepted Answer

A physical process; mixtures retain their individual properties.

Question 2

Calculate the sum $$302.5 \ 	ext{mL} + 6.55 \ 	ext{mL}$$, reporting your answer with the correct number of significant figures.

Accepted Answer

$$309.1 \ 	ext{mL}$$

Question 3

A piece of soap has a mass of $$18.75$$ ounces. What is this mass in kilograms? $$(16 \ 	ext{ounces} = 453.6 \ 	ext{g})$$

Accepted Answer

$$0.533 \ 	ext{kg}$$

Question 4

Which of the following is a chemical property?

Accepted Answer

Reactivity with acid

Question 5

Which of the following substances is a compound?

Accepted Answer

$$	ext{CO}_2$$

Question 6

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

Accepted Answer

A copper wire

Question 7

When a nitrogen atom forms a nitride ion, what happens to its electrons?

Accepted Answer

3 electrons are gained

Question 8

Which of the following elements does NOT occur as a diatomic molecule?

Accepted Answer

Helium

Question 9

Which set of elements below contains, respectively, an alkaline earth metal, a noble gas, and a transition metal?

Accepted Answer

Mg, Ne, Co

Question 10

How many protons, neutrons, and electrons are in an atom of $$^{197}	ext{Au}$$, the most common isotope of gold?

Accepted Answer

79 protons, 118 neutrons, 79 electrons

Question 11

Which of the following combinations of formula and name is incorrect?

Accepted Answer

Ammonium ion $$= 	ext{NH}_3$$

Question 12

What is the correct formula for the compound formed between iron(III) ion and the oxide ion?

Accepted Answer

$$	ext{Fe}_2	ext{O}_3$$

Question 13

What is the correct formula for the compound formed between copper(II) ion and the phosphide ion?

Accepted Answer

$$	ext{Cu}_3	ext{P}_2$$

Question 14

Which of the following is the correct formula for the compound with the name iron(II) phosphate?

Accepted Answer

$$	ext{Fe}_3(	ext{PO}_4)_2$$

Question 15

Which of the following is the correct name for the compound $$	ext{CoBr}_2$$?

Accepted Answer

Cobalt(II) bromide

Question 16

A sample of a certain alcohol is $$0.785 \ 	ext{g/mL}. $$What mass of the alcohol would have a volume of $$200.0 \ 	ext{mL}$$?

Accepted Answer

$$157 \ 	ext{g}$$

GOB Chemistry Exam Practice: Step-by-Step Guidance

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