Question 1

Which of the following best describes a pure compound as shown in a particle diagram?

Accepted Answer

A collection of identical molecules, each made of two or more elements.

Question 2

Which of the following is the correct product for the complete combustion of methane ($$CH_4$$)?

Accepted Answer

$$CO_2$$ and $$H_2O$$

Question 3

A student measures the mass of a sample as $$23.1 g $$and $$32.1 	imes 10$$^{-2}$$ g. What is the sum, expressed in scientific notation with correct significant figures?

Accepted Answer

$$23.4 g$$

Question 4

Which of the following is an example of a heterogeneous mixture?

Accepted Answer

Sand and iron filings

Question 5

What is the molecular geometry of ammonia ($$NH_3) $$according to VSEPR theory?

Accepted Answer

Trigonal pyramidal

Question 6

Which of the following is the correct electron dot structure for water ($$H_2O$$)?

Accepted Answer

O with two single bonds to H and two lone pairs

Question 7

A balloon with a volume of $$2.0 L at$$ $$25^	ext{o}C $$contains $$0.082$$ mol of gas. What is the pressure inside the balloon? (Use $$R = 0.0821 L$$·atm·mol$$^{-1}$$·K$$^{-1})$$

Accepted Answer

$$1.0$$ atm

Question 8

Which of the following is the correct formula for sodium chloride?

Accepted Answer

$$NaCl$$

Question 9

Which element is most likely to form a $$2+$$ ion?

Accepted Answer

Magnesium

Question 10

What is the molar mass of $$CO_2$$?

Accepted Answer

$$44 g/$$mol

Question 11

Which of the following is a chemical change?

Accepted Answer

Burning gasoline

Question 12

What is the correct Lewis structure for $$N_2$$?

Accepted Answer

A triple bond between two N atoms with one lone pair on each

Question 13

Which of the following is the correct product for the reaction: $$C_2H_4 + H_2$ \rightarrow$$ ?

Accepted Answer

$$C_2H_6$$

Question 14

Which of the following is an isomer of butane ($$C_4H_{10}$$)?

Accepted Answer

2-methylpropane

Question 15

What is the correct IUPAC name for the compound $$CH_3CH_2CH_2CH_3$$?

Accepted Answer

Butane

Question 16

Which of the following best describes the atomic number of an element?

Accepted Answer

The number of protons in the nucleus

Question 17

Which of the following is the correct formula for calcium phosphate?

Accepted Answer

$$Ca_3$$($$PO_4)_2$

Question 18

Which of the following is a physical property?

Accepted Answer

Density

Question 19

What is the correct electron configuration for sodium ($$Na$$)?

Accepted Answer

$$1s^2$$ $$2s^2$$ $$2p^6$$ $$3s^1$$

Question 20

Which of the following is the correct formula for the compound formed between potassium and bromine?

Accepted Answer

$$KBr$$

GOB Chemistry Exam Study Guide: Concepts, Calculations, and Practice

Guida di studio - Domande di pratica

Study guide - Flashcard