Chem Ch. 2: Measurements & Calculations

Which of these is the variable in an experiment designed to determine whether steel rusts more quickly near a lake or in a desert in one year?

• amount of rust

• time of exposure

• amount of water in the air

• mass of the steel

Which of these recorded observations is qualitative, rather than quantitative?

• A chemical reaction is complete in 2.3 s.

• The solid has a mass of 23.4 g.

• The compound melts at 87.5°C.

• Iron is denser than aluminum.

Which of these terms best describes the following statement? “A solution of the unknown compound turned litmus paper blue.”

• hypothesis

• model

• quantitative observation

• qualitative observation

Theories are considered successful only if they

• can be used to make accurate predictions.

• can be stated in simple terms.

• can be written in the form of an equation.

• have been accepted by all scientists.

Tags

NGSS.HS-PS2-1

The unit cm³ is used to express

• length

• mass

• volume

• time

The SI base units for time and temperature are

• hour and degree Celsius.

• second and degree Celsius.

• hour and kelvin.

• second and kelvin.

Which of these shows SI unit prefixes arranged in order from smallest to largest?

• centi, milli, kilo

• milli, centi, kilo

• kilo, milli, centi

• kilo, centi, milli

A sample of bismuth has a mass of 343 g and a volume of 35.0 cm3. What is the density of bismuth? ( $D=\frac{m}{v}$  )

• 0.102 g/cm³

• 9.80 g/cm³

• 378 g/cm³

• 1.20 ´ 104 g/cm³

The conversion factor  would be used to change $\frac{1\ L}{10^3\ mL}$  

• milliliters to liters.

• liters to milliliters.

• units of volume to units of length.

• units of length to units of volume.

An object’s weight is a measure of

• the force with which it is attracted by gravity.

• the pressure exerted on a scale.

• the amount of material per unit volume.

• the force causing the object to move.

Tags

NGSS.HS-PS2-4