Log in
Sign up for FREE
arrow_back
Library

C5 Energy Changes

star
star
star
star
star
Last updated 4 months ago
33 questions
4.5.1.1 Energy transfer during exothermic and endothermic reactions
1
4.5.1.1
1
4.5.1.1
2
4.5.1.1
1
4.5.1.1
1
4.5.1.1
2
4.5.1.1
1
4.5.1.1
1
4.5.1.1
1
4.5.1.1
1
4.5.1.1
1
MS2b
WS3.7
1
4.4.1.2
4.5.1.1
WS3.5
1
WS4.1
6
WS3.5
WS3.8
1
4.5.1.1
1
4.5.1.1
1
4.5.1.1
MS2b
4
4.5.1.1
4.5.1.3
2
4.5.1.1
WS2.6
4.5.1.2 Reaction profiles
1
4.5.1.2
1
4.5.1.2
1
4.5.1.2
1
4.5.1.2
1
4.5.1.2
1
4.5.1.2
1
4.5.1.2
4.5.1.3 The energy change of reactions
4.5.2.1 Cells and batteries
1
4.5.2.1
1
4.5.2.1
1
4.5.2.1
1
4.5.2.1
4.5.2.2 Fuel cells
1
4.5.2.2
1
4.5.2.2
6
4.5.2.2
Question 1
1.

Question 2
2.

Question 3
3.

Question 4
4.

Question 5
5.

Question 6
6.

Question 7
7.

Question 8
8.

Question 9
9.

Question 10
10.

Question 11
11.

A student investigated the reactivity of metals with hydrochloric acid.This is the method used.
1.   Measure 50 cm3 of hydrochloric acid into a polystyrene cup.
2.   Measure the temperature of the hydrochloric acid.
3.   Add one spatula of metal powder to the hydrochloric acid and stir.
4.   Measure the highest temperature the mixture reaches.
5.   Calculate the temperature increase for the reaction.
6.   Repeat steps 1 to 5 three more times.
7.   Repeat steps 1 to 6 with different metals.

The table below shows the student’s results.


Calculate the mean temperature increase X for magnesium in the table above.
Do not include the anomalous result in your calculation.

Question 12
12.
Determine the order of reactivity for the metals cobalt, magnesium and zinc.

Use the table from the previous question

Most:_______
Middle:_______
Least:_______
Question 13
13.

Question 14
14.

Question 15
15.
a. _______
b. _______
c. _______
Question 16
16.

Question 17
17.

Calculate the mean of the temperature change results. Do NOT use anomalies.

Question 18
18.

A student is given three metals, X, Y and Z to identify.

The metals are magnesium, iron and copper.

Plan an investigation to identify the three metals by comparing their reactions with dilute hydrochloric acid.

Your plan should give valid results.

Question 19
19.

Complete the table

Question 20
20.

Question 21
21.

Question 22
22.

Question 23
23.

Question 24
24.

• draw the reaction profile
• draw an arrow to show the overall energy change (label this E)
• draw an arrow to show the activation energy (label this A)

CH4 + H2O → CO + 3H2

Energy change = +208 kJ/mol

Question 25
25.

What is the energy change of this reaction?

Question 26
26.

• draw the reaction profile
• draw an arrow to show the overall energy change (label this E)
• draw an arrow to show the activation energy (label this A)

3H2 + N2 → 2NH3

Energy change = –76 kJ/mol

In a chemical cell, also called a voltaic cell, the substance that is most easily
oxidised will give up its electrons to the external circuit and is the anode of the cell.
Question 27
27.

Question 28
28.

Question 29
29.

Question 30
30.

Question 31
31.
Question 32
32.

Question 33
33.
Other Answer Choices:
Electrolyte
Water
Cathode
Oxygen
Hydrogen
Anode
What happens to energy in an endothermic reaction?
Energy stays the same throughout the reaction.
Energy is released into the surroundings.
Energy transforms into a different type.
Energy is absorbed from the surroundings.
In an endothermic reaction, how does the temperature change?
The reaction has no temperature change.
The temperature s increases.
The temperature decreases.
What do exothermic reactions release during the reaction?
Energy in the form of heat
Solid products only
Energy in the form of light
Electricity for powering devices
In an exothermic reaction, how does the temperature change?
Temperature remains the same
The temperature increases.
The temperature decreases
A reaction where the surrounding temperature decreases. Is this an exo or endothermic reaction?
Neither
Both
Endothermic reaction
Exothermic reaction
An ice cube is melting on a warm day. Is this an exo or endothermic reaction?
Both
Neither
Exothermic reaction
Endothermic reaction
You feel heat when adding water to a chemical heat pack. Is this an exo or endothermic reaction?
Both
Exothermic reaction
Neither
Endothermic reaction
A chemical reaction that increases the outside temperature. Is it an exo or an endothermic reaction?
Both
Endothermic reaction
Neither
Exothermic reaction
From above, What type of variable is the volume of hydrochloric acid in this investigation?
Control
Dependent
Independent
A student investigated the temperature change when zinc reacts with copper sulfate solution.

The student used a different concentration of copper sulfate solution for each experiment.The student used the apparatus shown below.


The student:
•        measured 50 cm3 copper sulfate solution into a glass beaker
•        measured the temperature of the copper sulfate solution
•        added 2.3 g zinc
•        measured the highest temperature
•        repeated the experiment using copper sulfate solution with different concentrations.

The equation for the reaction is:
Zn(s)     +                 CuSO4(aq)               -->     Cu(s)       +              ZnSO4(aq)
zinc       +      copper sulfate solution    -->    copper      +    zinc sulfate solution

The student’s results are shown in the table below.



Describe and explain the trends shown in the student’s results.
The decomposition of hydrogen peroxide gives out energy to the surroundings

What type of reaction is this?
Displacement
Endothermic
Exothermic
Neutralisation
Endo or exo?
Endothermic
Exothermic
Endo or exo?
Endothermic
Exothermic
Endo or exo?
Endothermic
Exothermic
Endo or exo?
Endothermic
Exothermic
False