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