Sci 30 – Diploma Practice Calculations (Part 1 – Bio and Chem)
Make sure you have a calculator and I strongly urge you to bring a TI-83/84 calculator to the exam.
Calculations will often come as the Numeric Response Questions – read the instructions carefully on how to
enter your values. Nothing worse than doing all the hard work, getting the right answer, and putting it in
wrong. Remember the test goes in order  Bio, Chem, Physics, Environment
Biology
The only calculations in this unit will deal with percents when dealing with Punnet squares, so you probably
won’t need to bust out that calculator until you get to the chem.
1.
Cystic fibrosis is an autosomal recessive trait.
a) Both parents are heterozygous and do not display cystic fibrosis.
i.
Calculate the probability the first child of the parents above will receive at least one recessive
allele (i.e. be a carrier or have cystic fibrosis)
ii.
The probability the first child will have and display cystic fibrosis.
b) One parent has cystic fibrosis and the other is homozygous dominant.
i.
Calculate the probability the first child of the parents above will receive at least one recessive
allele (i.e. be a carrier or have cystic fibrosis)
ii.
The probability the first child will have and display cystic fibrosis.
c) Both parents have cystic fibrosis.
i.
Calculate the probability the first child of the parents above will receive at least one recessive
allele (i.e. be a carrier or have cystic fibrosis)
ii.
The probability the first child will have and display cystic fibrosis.
d) One parent has cystic fibrosis and the other is heterozygous.
i.
Calculate the probability the first child of the parents above will receive at least one recessive
allele (i.e. be a carrier or have cystic fibrosis)
ii.
The probability the first child will have and display cystic fibrosis.
Answers:
1. A. i) 75% ii) 25%
B. i) 100% ii) 0%
C. i) 100% ii) 100%
D. i) 100% ii) 50%
Chemistry
Three formulas in Chem. Two are found on the Acids/Bases Section (p.11) and the other is found on the
Stoichiometry section (p.10). They will ask at least two questions, one using either the pH or [H3O+] calculation
and the other a C=n/v titration calculation.
Remember, since the pH scale is logarithmic it means every step is a change of 10x. For instance, the hydronium
concentration of an acid going from 6.6 to 4.6 increases 100 times!
pH= -log[H3O+(aq)]
[H3O+(aq)] = 10(-pH)
C = n/V
2.
Calculate the pH with the hydronium concentration is 5.49 X 10-4 mol/L.
3.
Calculate the [H3O+] when the pH is 4.500.
4.
Calculate the pH with the hydronium concentration is 7.00 X 10-7 mol/L.
5.
Calculate the [H3O+] when the pH is 0.650
6.
Calculate the number of mols (n) of hydronium in 4.50L solution when the pH is 8.000. The number of
mols can be put in in the form a.bc × 10-d mols. The values of a, b, c, and d, are _______, ________, ________,
and ____________.
7.
A 3.50mol solution has a pH is 2.500. The volume can be put in in the form a.bc × 10d litres. The values
of a, b, c, and d, are _______, ________, ________, and ____________.
8.
Titration reveals that 11.6 mL of 3.0 mol/L acid is required to neutralize the sodium hydroxide in 25.0
mL of NaOH solution. What is the concentration of the NaOH solution?
9.
In a titration experiment, 22.0 mL of 2.40 mol/L base are required to neutralize 50.0mL of unknown
concentration acid. What is the concentration of the acid?
10. In a titration experiment, the burret runs the titrant 5 times, recording the following: 40.0mL, 40.2 mL,
40.1 mL, 44.0 mL, 39.9mL. What should the average titrant be if you only include accurate measurements
in the form ab.c mL. The values of a, b, and c are _____, ______, and ______.
11. The titration experiment uses the average of the titrant results (12.0mL, 11.9mL, 11.8mL) of a 7.00 mol/L
of HCl to neutralize a base. Calculate the concentration of 10.0mL solution of base.
Answers:
2) 3.260
7)
8) 1.39 mol/L
11) 8.33 mol/L
3) 3.16 X 10-5 mol/L
1
1
1
4) 6.155
5) 0.224 mol/L
3
9) 1.06 mol/L
10)
4
0
1
6)
4
5
0
8
Sci 30 – Diploma Practice Calculations (Part 2 – Physics and Environment)
Full solutions will be available at www.stachs.ca/mckennitt under Science 30. Answers are on the back of this
sheet.
Physics – Electricity and EM Spectrum
Lots of calculations in this section:
The first deals with field strength for electric and gravitational fields. Remember, the common mass and
radius for the Earth/Sun are in the data book right below the formulas. Will definitely get one question on
either the Electric Field or Gravitational Field Strength…. McKennitt’s money on it will be on the electric field
strength.
Then Ohm’s Law (V=IR) and the Power Law (P=IV). Energy can also be calculated from power (E=Pt), but
remember Energy can be measured in either Joules or kWh. Kilowatt-hours is not in the data booklet 
Resistance in a circuit will deal with series and parallel circuits. Identify first which type it is and then use the
appropriate formula. Remember adding resistors in series increases the total resistance, but adding resistors
on new branches in parallel circuits will decrease the total resistance….tricky, tricky, tricky….
The transformers questions will always deal with step-up or step-down transformers that increase or
decrease the voltage.
Only one formula on EM-Spectrum, v = λ f, but remember v=3 X108 m/s when you are dealing with any
wave on the EM spectrum (all of them – radio, infrared, visible, UV, x-ray, gamma)
12. On the Moon (radius=1.737 X 106 m), astronauts played golf to demonstrate differences in gravity. If the
mass of the moon is 7.36 X1022 kg, what is the magnitude of the gravitational field strength?
13. On Planet McKennitt (mass 4.50 X 109 kg), a communication satellite is orbiting at a radius of 4.50 X 103m
from the centre of the planet. What is the magnitude of the gravitational field strength? Put you answer
in the form a.bc × 10-d N/kg. The values of a, b, c, and d, are _______, ________, ________, and ____________.
14. On the surface of the Earth, what is the gravitational field strength?
15. If a negatively charged balloon has a charge of q=-0.450 Coulombs, what it the electric field strength,
when it is held:
a. 1.00 m away
b. 2.00 m away
c. 3.00 m away
16. If a positively charged balloon has a charge of q=+5.00 Coulombs, what it the electric field strength, when
it is held 20.0m away? Put you answer in the form a.bc × 10d N/C. The values of a, b, c, and d, are _______,
________, ________, and ____________.
17. A light bulb has a resistance of 4 ohms and a current of 2 A. What is the voltage across the bulb?
18. How many ohms of resistance must be present in a circuit that has 120 volts and a current of 10 amps?
19. You have a large flashlight that takes 4 D-cell batteries. If the current in the flashlight is 2 amps, what is
the resistance of the light bulb? (Hint: A D-cell battery has 1.5 volts.)
20. How many amperes does a 100 watt bulb require when operating on 120 volts?
21. An iron that heats with the power of 1200 watts at 120 volts is turned on. Will it blow a 15 ampere fuse?
22. Calculate the amount of power of an electric heating element, if the voltage required is 110 volts and the
heater’s resistance is 2.5 ohms. Put you answer in the form a.bc × 103 W. The values of a, b, and c, are
______, ________, and ____________.
23. Use the diagram below to answer the following problems.
a. What is the total voltage in each circuit?
b. How much current would be measured in each circuit if the light bulb has a resistance of 6 ohms?
c. How much current would be measured in each circuit if the light bulb has a resistance of 12 ohms?
d. Is the bulb brighter in circuit A or circuit B? Why?
24. How much electrical power is being dissipated by the light bulb in this circuit?
25. Calculate the resistance in the circuit below:
26. A circuit is shown on the right, made up of 3 resistors (20ohm, 30 ohm, and
50ohm.) The current is tested at 2A.
a) Calculate the total resistance
b) Calculate the voltage needed to power the circuit.
27. A television converts 12,000 joules of electrical energy into light and sound every minute. What is the
power of the television?
28. What energy is consumed in joules if a circuit uses 9.0V to run a 1.8A current for 30 seconds?
29. A dryer has a power rating of 5000 W and is run for 60 hours over the course of a summer.
a) Calculate the energy consumed in kWh.
b) If electricity costs $0.11/kWh, how much does it cost to run the dryer?
30. If the number of turns on a transformers primary ring is 200 and there are 500 turns on the secondary,
what is the new value of the voltage if the initial value was 110 V?
31. If you increasing the voltage from 2V to 20V, how many turns must be on the secondary ring if there were
40 turns on the initial ring?
32. A radio wave, a form of electromagnetic wave, has a frequency of 99.5MHz (9.95x107 Hz). What is its
wavelength?
33. A light wave travels through the air at a speed of 3.0 x108 m/s. Red light has a wavelength of about 6.6 x
10 -7 m. What is the frequency of red light? Put you answer in the form a.b × 10cd Hz. The values of a, b,
c, and d, are _______, ________, ________, and ____________.
34. An unknown wave has a frequency of 1.00 x 1016 Hz. What is the wavelength and where on the EM
spectrum would you expect to find this type of wave?
Answers
12) 1.63 N/kg
13)
15) a) 4.05 X 109 N/C
b) 1.01 X 109 N/C
c) 4.50 X 108 N/C
16)
17) 8V
19) 3 ohms
1
1
2
8
21) Won’t blow (only 10A)
1
4
8
14) 9.83 N/kg
8
18) 12 ohms
22)
4
4
20) 0.833 A
0
23) a) Circuit A: 6V
Circuit B: 12V
b) Circuit A: 1A
c) Circuit A: 0.5A
Circuit B: 1A
d) Bulb in Circuit B will be brighter – more current
24) 6.48 W
25) 12 Ohms
26) a) 100 ohms
b) 200V
27) 200 W
28) 486 J
29) a) 300 kWh
b) $33.00
30) 275V
31) 400 turns
32) 3.02 m
33)
34) 3 X 10-8 m, Ultraviolet
Circuit B: 2A
4
5
1
4
Energy and Environment
There are three formulas that are used:
The two major ones are:
The third (minor) formula is:
𝒆𝒇𝒇𝒊𝒄𝒊𝒆𝒏𝒄𝒚 % =
𝒐𝒖𝒕𝒑𝒖𝒕
𝑿𝟏𝟎𝟎
𝒊𝒏𝒑𝒖𝒕
Practice Problems:
35. What is the ∆fH° of the following:
a) 6 mols of octane
b) 2 mols of oxygen gas
36. Calculate the efficiency of a barbeque that produces 200 kJ of useful output energy for cooking when it
uses 600 kJ of input energy?
37. Calculate the chemical potential energy necessary of a power plant to output 2.9 X 1012J of energy if it is
21% efficient?
38. Calculate the energy change of the combustion reactions shown below.
a) 1__ C (s) + _1__ O2 (g) _1_ CO2 (g)
b) 1__ CH4 (s) + _2__ O2 (g) _1_ CO2 (g) + _2_ H2O (g)
39. Write a balanced nuclear reaction for the alpha decay and gamma decay of strontium-95.
40. Write a balanced nuclear reaction for the beta decay of neon-20.
41. According to the formula E=mc2, if 300.0J of energy is released in nuclear reaction, how much mass is
consumed in the process? Put you answer in the form a.bc × 10-15 kg. The values of a, b, and c, are
_______, ________, and ____________.
42. For oxygen-18, identify how many protons/neutrons/nucleons and write it in nuclear notation.
43. For the following, identify the unknown ???? particle and list which types of decay took place.
218
84Po
→ ? ? ? + −10e + 42He
44. Throrium-230 undergoes alpha decay.
a) Write out the nuclear reaction
b) Calculate the change in mass from the reactants to the products and identify if the reaction is
exothermic and endothermic.
c) Calculate the energy change. Put you answer in the form a.b × 10cd J. The values of a, b, c, and d, are
_______, ________, ________, and ____________.
Answers
35) a) -1500.6 kJ
b) 0 kJ
38) a) -393.5 kJ
b) -802.5 kJ
39)
95
38Sr
40)
20
10Ne
→
41)
3
3
42)
43)
214
83Bi,
0
−1e
+ 20
11Na
protons-8, neutrons-10, nucleons-18
alpha and beta decay
226
4
44) a) 230
90Th → 2He + 88Ra
b) 6.22 X 10-6 kg
c)
5
6
37) 1.39 X 1013 J of input
91
→ 42He + 00γ + 36
Kr
3
18
8O,
36) 33.3%
1
1