Practice Final

The charge on halogen ions is

-1

The specific heat of ice is 2.1 kJ/kg°C. When 50 kJ of heat is removed from 2 kg of ice initially at -5°C, the final temperature of the ice is

-17

A weightlifter raises a 200-kg barbell through a height of 2 m in 2.2 s. The average power he develops during the lift is

1.78 kW

A 1-kg mass has a KE of 1 J when its speed is

1/4 m/s

A total of 4900 J is expended in lifting a 50-kg mass. The mass is raised to a height of

10 m

A car starts from a speed of 10 m/s with an acceleration of 2 m/s2. The time needed for the car to reach 30 m/s is

10 s

In 6 min a person running at 10 km/h covers a distance of

1000 m

The number of oxygen atoms in a molecule of aluminum sulfate, Al2(SO4)3, is

12

A net horizontal force of 2000 N is applied to an 800-kg car at rest. The car's speed after 5 s will be

12.5 m/s

Two charges repel each other with a force of 10-6 N when they are 10 cm apart. When they are brought closer together until they are 2 cm apart, the force between them becomes

2.5x10^-5 N

A force of 2 N acts on a 2-kg object, initially at rest, for 2 s. During that time the object moves a distance of

2m

The electric energy stored in a 6-V battery rated at 20 Ah is

432 kJ

The density of air is 1.3 kg/m3. The air in a room 5 m long, 4 m wide, and 2.5 m high has a mass of

65kg

Ethanol boils at 172°F. The Celsius equivalent of this temperature is

78 C

The mass number of the nucleus Be 9/4 is

9

The voltage needed to produce a current of 8 A in a resistance of 12 ohms is

96 V

The chromate ion has the formula CrO42-. The formula of tin(II) chromate is

SnCrO4

Which of the following statements is not true?

a proton in an atom circulates around the nucleus

A solution of carbon dioxide, CO2, in water is

acidic

The reaction of an alcohol with an organic acid produces

an ester

The name of the compound Ca3N2 is

calcium nitride

The mass of a positron is

equal to the mass of an electron

A vertical column in the periodic table is called a

group

When first proposed, a scientific idea is usually called a

hypothesis

When equivalent amounts of a strong acid and a strong base react, the resulting solution is

neutral

A horizontal row in the periodic table is called a

period

The watt is a unit of

power

Nitrogen is needed by plants mainly to manufacture

proteins

Which of the following is a heterogeneous mixture?

soil