Grade 11 SAT 1st Term Revision 2023

1

100

The Greek letter Δ stands for ____________

"Change in"

200

An Insulated device used to measure the amount of heat absorbed or released during a chemical or physical process.

Calorimeter

300

What is the system, surroundings and universe in a flask of HCl

system: flask containing HCl

surroundings: everything else other than the flask

universe: system + surroundings

400

DHvaporization of water is 40.7 what is the DHcondensation

DH cond= -40.7

500

Use the information below to determine ΔH for the reaction represented by the equation .

• 2NO(g)+O2(g)⇋2NO2(g) (Use summation equation)

the enthalpy of formation of the compounds and elements: 

NO        ΔH_f= 90.25

O2        ΔH_f= 0

NO2      ΔH_f=33.18

ΔH = ΔH_{f (products) -} ΔH_{f (reactants)}

ΔH= (2x33.18) - [0 + (90.25 x 2)]

ΔH= 66.36 - 180.4 = -114.04

2

100

In  Gibbs Free Energy Calculations, temperature is expressed in ___________

Kelvin

200

The standard enthalpy of formation of an element is

zero

300

the products are at a higher energy level than the reactants

Endothermic reaction

400

Calculate energy absorbed by 8 g of copper when heated from 10C to 40C. specific heat =0.384J/(g.C)

q = cp x m x DT

q = 0.384 x 8 x 30

q = 92 J

500

energy released or absorbed as heat when one mole of a compound is burned in oxygen

Enthalpy of combustion

3

100

What is the value of ΔG at 300 K for a reaction in which ΔH = –150 kJ/mol and ΔS= +2.00 kJ/mol·K?

 ΔG= ΔH - TΔS

ΔG= -150 - (300 x 2) = -750

200

Compounds with a Highly negative enthalpy of formation

Very stable compound

300

Compounds with a Large positive enthalpy of formation

Unstable compound

400

Entropy increases when:

1. gases have more room to move

2. solid dissolves in a solution

3. total moles of gas products are more than moles of gas reactants

4. temperature increases

500

Suppose that a chemical equation can be written as the sum of two other chemical equations. If two reactions have  values of –658 kJ and +458 kJ, what is  for the reaction that is their sum?

-658 + 458 = -200KJ

4

100

Phase State that has highest entropy

Gases

200

Combustion reactions are always defined in terms of _____________

one mole of reactant

300

A measure of the possible ways that the energy of a system can be distributed

Entropy

400

Study of heat changes that accompany chemical reactions and phase changes

thermochemistry

500

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

0 - 100 = -100KJ

5

100

DH is +ve 

Endothermic reaction

200

For the reaction  A(g) + B(g) --> 2C(g) + D(g) + energy, what is the value of ΔS and ΔH?

ΔS is positive

ΔH is negative

300

energy flowing from warm to cold

heat

400

Energy absorbed in breaking bonds  

Energy released in forming bonds 

What is Endothermic?

What is Exothermic?

500

Use equations (a and b) to calculate ΔH for the following reaction (using Hess’s Law):

Hg2Cl2(s)⟶2Hg(l)+Cl2(g)

from the following information:

Equations a and b

HgCl2(s) ⟶ Hg(l)+Cl2(g)          ΔH=224 kJ

Hg2Cl2(s) ⟶ Hg(l)+HgCl2(s)     ΔH= 41.2 kJ

Add equations a and b and their ΔH

ΔH=224 kJ

ΔH= 41.2 kJ

224 + 41.2 = 265.2KJ