Unit 11: Thermochemistry

The energy stored in chemical bonds is called ____ potential energy

• chemical

• kinetic

• potential

• substantial

Tags

NGSS.HS-PS1-4

Calculate the standard enthalpy change (ΔH) given the following: total enthalpy of the reactants is -82 kJ and the total enthalpy of the products is -912 kJ.

• 830 kJ

• 994 kJ

• -994 kJ

• -830 kJ

Tags

NGSS.HS-PS1-4

NGSS.HS-PS3-1

The _______ is defined as the system along with the surroundings.

• universe

• surroundings

• earth

• system

Heat moves from _____ to _____.

• freezing to warm

• warm to cold

• cold to hot

• none of the above

Tags

NGSS.HS-PS3-4

The total enthalpy of the products in a reaction is 100 kJ, and the total enthalpy of the reactants is 0 kJ. What is ΔH of the reaction?

• -393.5 kJ

• 393.5 kJ

• 100 kJ

• -100 kJ

Tags

NGSS.HS-PS3-1

When the change in enthalpy (ΔH) is positive, the reaction is _____. When the change in enthalpy (ΔH) is negative, the reaction is _____.

• exothermic/endothermic

• endothermic/exothermic

Tags

NGSS.HS-PS1-4

The temperature of a sample of a compound with a mass of 1.0 g changed from 25°C to 50.4°C and absorbed 114 J of energy. What is the specific heat of the compound?

• 8.49 J/g°C

• 4.48 J/g°C

• 10.4 J/g°C

• 21.4 J/g°C

Tags

NGSS.HS-PS3-4

How much heat is released by 15.5 g of water when its temperature is cooled from 50°C to 20°C? The specific heat of water is 4.184 J/g°C.

• -1.946 J

• -1946 J

• -194.6 J

• -194600 J

Tags

NGSS.HS-PS3-4

NGSS.HS-PS3-1

An exothermic reaction releases 85.0 J of energy. How many calories of energy are released into the reaction?

• 0.0519 cal

• 336.8 cal

• 80.5 cal

• 20.3 cal

Tags

NGSS.HS-PS1-4

When a nugget of pure gold is cooled from 842.26°C to 35°C, it released 5200.0 J of energy. The specific heat of gold is 0.129 J/g°C. Find the mass of the gold nugget.

• 208 g

• 50 g

• 67 g

• 11 g

Tags

NGSS.HS-PS3-4