Q: Which of the following numbers have four significant figures?

1.750 \times $$10^{-9}$$ \text{ m}

Q: A device records data according to $$D = t \times r. If$$ $$D = 9.00 \times 10^6$ bytes and r = 4500$ bytes/s, what is the time t$ required, in scientific notation and correct significant figures?

$$t = \frac{9.00 \times 10^6$}{4500} = 2.00 \times 10^3$ \text{ s}$$

Q: What is the mass of a neutron in kilograms?

$$1.675 \times 10$$^{-27}$$ \text{ kg}$$

Q: Which conversion factor would you use to convert 5.0 lb to grams?

$$1 \text{ lb} = 453.59 \text{ g}$$

Q: Which equation correctly converts Fahrenheit to Celsius?

$$T_{\text{C}} = (T_{\text{F}} - 32) \times \frac{5}{9}$$

Question 1

Which of the following statements about liquids is INCORRECT?

Accepted Answer

They consist of particles that are relatively far apart.

Question 2

Given the equation $$\frac{PV}{1.5} = 8.3T$$, solve for $$T as a $$simple fraction.

Accepted Answer

$$\frac{PV}{12.45} = T$$

Question 3

Which of the following is a chemical property?

Accepted Answer

Burning wood in a fireplace

Question 4

Perform the following calculation and report the answer in the correct number of significant figures: $$\frac{(8.0 	imes 10^2$)(4.1011 - 4.1013)}{0.000250}$$

Accepted Answer

$$-6.40$$

Question 5

Which set of powers of 10 (in meters) best matches the sizes of the following objects: hydrogen atom, bacterium, and an office desk?

Accepted Answer

$$10^{-10}$$, $$10^{-6}$$, $$10^{0}$$

Question 6

Which of the following numbers have four significant figures?

Accepted Answer

1.750 	imes $$10^{-9}$$ 	ext{ m}

Question 7

Which mixture is homogeneous?

Accepted Answer

Sugar dissolved in water

Question 8

A chemist needs to know the mass of a sample of $$	ext{Na}_2	ext{SO}_4 to 4 $$significant digits. The scale shows 10.20 g. What is the correct mass?

Accepted Answer

10.20 	ext{ g}

Question 9

Which of the following sentences is INCORRECT?

Accepted Answer

A compound is a mixture of elements.

Question 10

Which sketch best represents hydrogen chloride (HCl) at $$-66.0^\circ 	ext{C}$$, given its melting point is $$-114.8^\circ 	ext{C}$$ and boiling point is $$-85.1^\circ 	ext{C}$$?

Accepted Answer

Sketch 2 (randomly arranged HCl molecules, close together)

Question 11

A device records data according to $$D = t 	imes r. If$$ $$D = 9.00 	imes 10^6$ bytes and r = 4500$ bytes/s, what is the time t$ required, in scientific notation and correct significant figures?

Accepted Answer

$$t = \frac{9.00 	imes 10^6$}{4500} = 2.00 	imes 10^3$ 	ext{ s}$$

Question 12

Which of the following is an example of a physical change?

Accepted Answer

Melting ice

Question 13

Which prefix represents $$10^{-6}$$?

Accepted Answer

micro ($$\mu)$$

Question 14

What is the mass of a neutron in kilograms?

Accepted Answer

$$1.675 	imes 10$$^{-27}$$ 	ext{ kg}$$

Question 15

Which conversion factor would you use to convert 5.0 lb to grams?

Accepted Answer

$$1 	ext{ lb} = 453.59 	ext{ g}$$

Question 16

Which element is in group 2A and period 3 of the periodic table?

Accepted Answer

Magnesium (Mg)

Question 17

If a marble is placed in a graduated cylinder and the water level rises from 100.0 mL to 104.0 mL, what is the volume of the marble?

Accepted Answer

$$4.0 	ext{ mL}$$

Question 18

Which of the following is a heterogeneous mixture?

Accepted Answer

Salt mixed with pepper

Question 19

Which equation correctly converts Fahrenheit to Celsius?

Accepted Answer

$$T_{	ext{C}} = (T_{	ext{F}} - 32) 	imes \frac{5}{9}$$

CHEM 1200 Exam 1 Study Guidance – General Chemistry Concepts and Problem Solving

Guida di studio - Domande di pratica

Study guide - Flashcard