Honors Unit 8_States of Matter & Thermochemistry

ΔH value in an endothermic reaction is a positive number.

• True
• False

Which statement is true regarding endothermic reactions?

• a) Temperature change is positive and enthalpy change is positive

• b) Temperature change is positive and enthalpy change is negative

• c) Temperature change is negative and enthalpy change is positive

• d) Temperature change is negative and enthalpy change is negative

What is ΔH if 5.5 grams H₂O(l) is formed from this reaction?

H₂(g) + ½ O₂(g) → H₂O(l) ∆H = -285.8 kJ

• -8600 kJ

• -420 kJ

• -87 kJ

• -98 kJ

What will happen to the volume of a gas under constant temperature if the pressure increases?

• Increase
• Decrease
• Nothing
• Explosion!

At room temperature (25ºC) and pressure (1 atm), what volume would 14g of nitrogen gas occupy?

• 14 L

• 24 L

• 48 L

• 12 L

Which is true about kinetic theory of gases?

• temperature determines the kinetic energy of particles
• particles lose energy when they collide with one another
• molar mass determines the kinetic energy of particles
• container size determines kinetic energy of the particle

Compressing a gas makes the pressure _______.

• increase
• decrease
• stay the same
• I don't know

When you heat a gas, the particles' energy ________ . This causes the particles to _______________.

• increases, have fewer collisions
• increases, have more collisions
• decreases, have more collisions
• remain the same, have more collisions

energy in endothermic reactions are

• released
• ended
• absorbed

How many grams of CO gas will occupy a volume of 2.5 L, if 1.8 mol of CO gas occupies 3.6 L?

• 1.25 g

• 35 g

• 73 g

• 2.6 g