Q: Which of the following is an example of an observation?

Water boils at 100 $$^\\circC.$$

Q: Convert $$25.0 \\ ^\\circC to $$Kelvin and to Fahrenheit scale.

$$298.15 \\ K$$ and $$77.0 \\ ^\\circF$$

Question 1

Which of the following statements about the scientific method is TRUE?

Accepted Answer

The scientific method emphasizes observation and experimentation as the way to understand the world.

Question 2

Which statement about a hypothesis is TRUE?

Accepted Answer

A hypothesis is a tentative explanation that can be tested by experiments.

Question 3

Which of the following is an example of an observation?

Accepted Answer

Water boils at 100 $$^\circC.$$

Question 4

Which of the following represents a compound?

Accepted Answer

Water

Question 5

The correct scientific notation for the number 0.000423 is:

Accepted Answer

$$4.23 \times 10$$^{-4}$$

Question 6

The correct decimal representation of $$6.423 \times 10$$^{4}$$ is:

Accepted Answer

64,230

Question 7

The correct number of significant figures in the number 0.00250 is:

Accepted Answer

3

Question 8

How many significant digits should be reported in the answer to the following calculation? $$4.23 \times 1.7 \div 2.56$$

Accepted Answer

2

Question 9

The correct prefix for the multiplier 0.000001 is:

Accepted Answer

micro-

Question 10

What is the base SI unit for length?

Accepted Answer

meter

Question 11

A mass has dimensions of 10.0 in $$\times 20.0 in$$ $$\times 8.0 in. $$Given that there are four feet in a yard, what is the volume of the mass in $$m^3$$?

Accepted Answer

$$0.0262$$ $$m^3$$

Question 12

Given the density of Au is $$19.3 \ g/cm^3$, determine the mass of gold (in grams) in an ingot with the dimensions of 10.0$$ \ cm \times 10.0 \ cm \times 2.0 \ cm$$.

Accepted Answer

$$3860 \ g$$

Question 13

Determine the density of an object that has a mass of $$181.8 \ g$$ and displaces $$121.2 \ mL of $$water when placed in a graduated cylinder.

Accepted Answer

$$1.50 \ g/mL$$

Question 14

Which of the following statements about matter is FALSE?

Accepted Answer

Matter exists only as solids.

Question 15

Classify each as a pure substance or a mixture. If it is a pure substance, identify it as an element or a compound. If it is a mixture, identify it as homogeneous or heterogeneous: (a) air, (b) table salt, (c) iron, (d) salad.

Accepted Answer

Air: mixture, homogeneous; Table salt: compound; Iron: element; Salad: mixture, heterogeneous

Question 16

Classify each change as physical or chemical: (a) the tearing of paper, (b) a match igniting fireworks, (c) a can forming a penny when placed in a chemical wash, (d) coffee is brewed.

Accepted Answer

a) physical, b) chemical, c) chemical, d) chemical

Question 17

A chemist mixes $$4.0 \ g of $$potassium iodide by combining $$1.9 \ g of $$potassium with $$2.1 \ g of $$iodine. Show that these results are consistent with the law of conservation of mass.

Accepted Answer

The total mass of reactants equals the mass of product: $$1.9 \ g + 2.1 \ g = 4.0 \ g.$$

Question 18

Energy that is associated with the motion of an object is called:

Accepted Answer

Kinetic energy

Question 19

Convert $$25.0 \ ^\circC to $$Kelvin and to Fahrenheit scale.

Accepted Answer

$$298.15 \ K$$ and $$77.0 \ ^\circF$$

Introduction to Chemistry: Pre-Test Study Guide

Guida di studio - Domande di pratica

Study guide - Flashcard