Grade 11 Chemistry Homework Practice: Electricity

Electricity Homework Practice

Grade 11 Chemistry Electricity Homework Practice Advanced 40 Questions 14 Views

Classroom Worksheet

Grade 11 Chemistry Homework Practice: Electricity

Electricity Homework Practice

Name____________________________

Date________________

Score______ / 40

Grade: Grade 11

Subject: Chemistry

Topic: Electricity

Time: 20 Minutes

Difficulty: Advanced

Questions: 40

Instructions:
Answer all 40 questions neatly. Show your work where calculations are required. Use correct chemistry and electricity vocabulary. Unless told otherwise, assume room temperature and standard lab conditions.

Skills Practiced:

Electricity
Chemistry
Critical Thinking
Problem Solving

1Question

Define the term electric current.

2Question

What is the SI unit of electric current?

3Question

State the unit used to measure electric potential difference.

4Question

State the unit used to measure electrical resistance.

5Question

What type of particles carry current in a metallic conductor?

6Question

What type of particles carry current in an aqueous electrolyte?

7Question

Write the formula that links current, charge, and time.

8Question

A charge of 12 coulombs passes through a wire in 3 seconds. Calculate the current.

9Question

A current of 2 A flows for 10 s. Calculate the charge transferred.

10Question

State Ohm’s law.

11Question

Write the formula for electrical resistance in terms of voltage and current.

12Question

A resistor has a potential difference of 9 V and a current of 3 A. Calculate its resistance.

13Question

A wire has a resistance of 8 Ω and carries a current of 0.5 A. Calculate the potential difference across it.

14Question

Define electrolyte.

15Question

Explain why solid sodium chloride does not conduct electricity, but molten sodium chloride does.

16Question

What is meant by a conductor in chemistry and electricity?

17Question

A student says distilled water is a good conductor. Is this correct? Explain briefly.

18Question

Describe what happens to the ions in copper(II) sulfate solution during electrolysis.

19Question

What is electrolysis?

20Question

Name the electrode at which reduction occurs during electrolysis.

21Question

Name the electrode at which oxidation occurs during electrolysis.

22Question

In electrolysis, what is the charge of the anode in an electrolytic cell?

23Question

In electrolysis, what is the charge of the cathode in an electrolytic cell?

24Question

Write the half-equation for the reduction of copper(II) ions to copper metal.

25Question

Write the half-equation for the oxidation of chloride ions to chlorine gas.

26Question

During electrolysis of molten lead(II) bromide, what forms at the cathode?

27Question

During electrolysis of molten lead(II) bromide, what forms at the anode?

28Question

A current of 1.5 A flows through a solution for 40 minutes. Calculate the charge transferred.

29Question

A current of 0.80 A passes through an electrolytic cell for 25 minutes. Calculate the charge transferred.

30Question

Calculate the number of moles of electrons transferred when 9650 C of charge pass through a circuit. Use Faraday constant = 96500 C mol−1.

31Question

How many moles of electrons are transferred when 2 Faradays of charge pass through a cell?

32Question

Calculate the mass of copper deposited when 1.0 mol of Cu2+ ions is reduced. Relative atomic mass of copper = 63.5.

33Question

How many moles of electrons are needed to deposit 0.50 mol of copper from Cu2+ ions?

34Question

Calculate the mass of copper deposited when 0.25 mol of copper is formed.

35Question

A copper-plating process uses Cu2+ ions. How many moles of copper are deposited when 0.30 mol of electrons are supplied?

36Question

A current of 2.0 A is passed through copper(II) sulfate solution for 9650 s. Calculate the charge transferred and the moles of electrons.

37Question

Using the result in Question 36, calculate the moles of copper deposited.

38Question

Calculate the mass of copper deposited in Question 37. Relative atomic mass of copper = 63.5.

39Question

Explain why an electrolytic cell requires an external power source.

40Question

A student electrolyzes molten magnesium chloride. Predict the products at each electrode and explain why these products form.

Answer Key

#	Answer
1	The rate of flow of electric charge through a circuit.
2	ampere (A)
3	volt (V)
4	ohm (Ω)
5	Electrons
6	Ions
7	I = Q / t
8	I = Q/t = 12/3 = 4 A
9	Q = It = 2 × 10 = 20 C
10	The potential difference across a conductor is directly proportional to the current through it, provided temperature and other physical conditions remain constant.
11	R = V / I
12	R = V/I = 9/3 = 3 Ω
13	V = IR = 0.5 × 8 = 4 V
14	A substance that conducts electricity when molten or in aqueous solution because it contains mobile ions.
15	In solid sodium chloride the ions are fixed in a crystal lattice and cannot move; when molten, the ions are free to move and carry charge.
16	A material that allows electric charge to flow easily because it has mobile charge carriers.
17	No. Distilled water has very few ions, so it is a very poor conductor.
18	Cu2+ ions move to the cathode and gain electrons; SO4^2− ions move to the anode, although they often remain spectator ions depending on the electrode and conditions.
19	The decomposition of an ionic compound by the passage of an electric current through it when molten or in solution.
20	Cathode
21	Anode
22	Positive
23	Negative
24	Cu2+ + 2e− → Cu
25	2Cl− → Cl2 + 2e−
26	Lead metal
27	Bromine
28	Q = It = 1.5 × 2400 = 3600 C
29	Q = It = 0.80 × 1500 = 1200 C
30	n = Q/F = 9650/96500 = 0.10 mol e−
31	2.0 mol e−
32	1.0 mol Cu is deposited, so mass = 63.5 g
33	0.50 mol Cu2+ requires 1.0 mol e−, because Cu2+ + 2e− → Cu
34	mass = 0.25 × 63.5 = 15.875 g, approximately 15.9 g
35	0.30 mol e− deposits 0.15 mol Cu, because 2 mol e− deposit 1 mol Cu
36	Q = It = 2.0 × 9650 = 19300 C; n = Q/F = 19300/96500 = 0.20 mol e−
37	0.20 mol e− deposits 0.10 mol Cu
38	mass = 0.10 × 63.5 = 6.35 g
39	Because the electrolysis reaction is non-spontaneous and requires electrical energy to force electrons through the circuit and drive the decomposition reaction.
40	At the cathode, magnesium metal forms because Mg2+ ions gain electrons. At the anode, chlorine gas forms because Cl− ions lose electrons. The ions move to opposite electrodes according to their charges during electrolysis.