Q: Express 0.000000120 m in scientific notation and using an appropriate metric prefix.

$$1.20 \times 10$$^{-7}$$ m; 120 nanometers (nm)

Q: A sample of water is heated from 20$$^\circC to 45$^\circC. If $$the mass of water is 95 kg, how many calories are required? (Specific heat of water = 1 cal/g$$^\circC)$$

$$95,000 \times 25 = 2,375,000$$ cal

Q: Which of the following is the correct formula for calculating the amount of heat required to raise the temperature of a substance?

$$q = m \times c \times \Delta T$$

Question 1

Which of the following best describes a chemical change?

Accepted Answer

Iron rusting when exposed to air

Question 2

A sample of matter has a definite volume but no definite shape. Which state of matter does this describe?

Accepted Answer

Liquid

Question 3

Which of the following is a homogeneous mixture?

Accepted Answer

Salt water

Question 4

Which of the following is the correct chemical symbol for sodium?

Accepted Answer

Na

Question 5

Which of the following best represents a chemical reaction?

Accepted Answer

2H$$_2O (l$$) $$\xrightarrow{electricity} 2H$_2 (g) + O$_2 (g)$$

Question 6

Express 0.000000120 m in scientific notation and using an appropriate metric prefix.

Accepted Answer

$$1.20 	imes 10$$^{-7}$$ m; 120 nanometers (nm)

Question 7

How many significant figures are in the measurement 0.02907 mL?

Accepted Answer

4

Question 8

A patient weighs 160 lb. What is their mass in kilograms? (1 kg = 2.205 lb)

Accepted Answer

$$160 \div 2.205 = 72.6 kg$$

Question 9

Convert a temperature of 104$$^\circF to $$Celsius using the formula $$^\circC$$ $$= \frac{5}{9} ( ^\circF$$ $$- 32 ).$$

Accepted Answer

$$40^\circC$$

Question 10

A sample of water is heated from 20$$^\circC to 45$^\circC. If $$the mass of water is 95 kg, how many calories are required? (Specific heat of water = 1 cal/g$$^\circC)$$

Accepted Answer

$$95,000 	imes 25 = 2,375,000$$ cal

Question 11

Which of the following statements about density is correct?

Accepted Answer

Density is mass divided by volume.

Question 12

A urine sample has a density of 1.020 g/mL. What is its specific gravity?

Accepted Answer

1.020

Question 13

Which of the following is an example of a derived SI unit?

Accepted Answer

Density (g/cm$$^3)$$

Question 14

A child is 21.5 inches long at birth. Convert this length to centimeters. (1 in = 2.54 cm)

Accepted Answer

$$21.5 	imes 2.54 = 54.6 cm$$

Question 15

Which of the following best describes the difference between mass and weight?

Accepted Answer

Mass is the amount of matter in an object; weight is the gravitational force on that object.

Question 16

How many significant figures should the result of $$13.75 \div 18$$ have?

Accepted Answer

2

Question 17

A solution contains 0.0026 g of phosphorus. Express this value in milligrams using scientific notation.

Accepted Answer

$$2.6 	imes 10$$^{0}$$ mg

Question 18

Which of the following is the correct formula for calculating the amount of heat required to raise the temperature of a substance?

Accepted Answer

$$q = m 	imes c 	imes \Delta T$$

Question 19

A sample of isopropyl alcohol has a mass of 25.0 g and a density of 0.7855 g/mL. What is its volume in mL?

Accepted Answer

$$25.0 \div 0.7855 = 31.8 mL$$

Chapter 1: Matter and Measurements – GOB Chemistry Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard