Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

IGCSE Science > Equations > Flashcards

Equations Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

Magnification and size of biological specimens using millimetres as units

A

Magnification = lens x times eyepiece x

eg 40 x 10 = magnification of 400

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Density

A

Mass/volume

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Hooke’s law

A

Force = constant x extension

F = kx

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Photosynthesis

A

Carbon dioxide + water + energy in the presence of chlorophyll and sunlight -> glucose + oxygen

6CO2 + 6H2O -> C6H12O6 + 6O2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Aerobic respiration

A

Glucose + oxygen -> carbon dioxide + water + energy

C6H12O6 + 6O2 -> 6CO2 + 6H2O + energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Reactions of acids

A

Acid + metal oxide -> salt + water
Acid + metal hydroxide -> salt + water
Acid + metal -> salt + hydrogen
Acid + metal carbonate -> salt + carbon dioxide + water
Acid + metal hydrogen carbonate -> salt + carbon dioxide + water
Acid + ammonia solution -> ammonium salt + water

Salt = metal nonmetal
eg hydrochloric + sodium = sodium chloride+water
acid hydroxide

When hydrochloric acid is neutralised, the salt formed is a metal CHLORIDE
When nitric acid is neutralised, the salt formed is a metal NITRATE
When sulphuric acid neutralised, the salt formed is metal SULPHATE.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Litmus paper indications

A

Red Litmus Blue Litmus
Acidic solution Stays red Turns red
Neutral solution Stays red Stays blue
Alkaline solution Turns blue Stays blue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Electrode products in the electrolysis of:

  • molten lead (ii) bromide
  • aqueous copper chloride
A 
Molten lead (ii) bromide 
PbBr2

Cathode
Pb2+ (l) + 2e- -> Pb (l)

Anode
2Br- (l) -> Br2 (g) + 2e-

  • lead metal at the negative electrode
  • The lead will form as a liquid at the bottom of the reaction vessel.
  • bromine (Br2) at the positive electrode
  • The bromine appears as a brown gas at the positive electrode.

Aqueous copper chloride
CuCl2 -> Cu + Cl2

At the cathode Cu is reduced
Cu2+ (aq) + 2e- -> Cu (s)

At the anode Cl is oxidised
2Cl- (aq) -> Cl2 (g) + 2e-

The products of this electrolysis are:

copper metal at the negative electrode

The copper forms as a brown solid on the negative electrode.

chlorine gas (Cl2) at the positive electrode

The chlorine appears as a gas with a characteristic smell at the positive electrode.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

PRECIPITATION REACTIONS
Identify usings tests…
-Aqueous cations: copper (ii), iron (ii), iron (iii) and zine
-Anions: carbonate, chloride
-Gases: carbon dioxide, chlorine, hydrogen, oxygen

A

Aqueous cations:

  • Copper (Cu2+). Effect of aq sodium hydroxide = light blue ppt. Insoluble in excess. Effect of aq ammonia = light blue ppt. Soluble in excess, giving a dark blue solution.
  • Iron (Fe2+). Effect of aq sodium hydroxide = green ptt. Insoluble in excess. Effect of aq ammonia = green ppt. insoluble in excess.
  • Iron (Fe 3+). Effect of aq sodium hydroxide = red-brown ppt. Insoluble in excess. Effect of aq ammonia = red-brown ppt, insoluble in excess.

Anions

  • Carbonate. Add dilute acid, then limewater. Results = bubbles, CO2 produced.
  • Choride. Acidify with dilute nitric acid, then add aqueous silver nitrate. White ppt

Gases

  • Carbon dioxide. Turns limewater milky
  • Chlorine. Bleaches damp litmus paper
  • Hydrogen. “pops” with a lighted splint.
  • Oxygen. Relights a glowing splint.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Name, identify and draw the structures of methane, ethane and ethene

A 
Methane:
CH4
      H
       |   
H - C - H
      |
     H
Ethane:
C2H6
       H    H
        |     |
H  -  C - C - H
        |     |
       H    H
Ethene:
C2H4
H          H
   \        /
    C = C
   /        \
 H        H
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Sped (from total time/total distance)

A

S = d/t

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Work out distance travelled in a speed/time graph

A

Area under the graph = distance.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q 
What is 
-energy
-work 
-power
measured in.
A

Energy = joules (J)
Work done = joules (J)
Power = Watts (W)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Kinetic energy equation

A

K.E. = 1/2mv^2

= 1/2 x mass x velocity^2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Potential energy equation

A

P.E. = mgh

= mass x gravity x height.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Efficiency equation

A

Efficiency = (useful energy)/(total energy) x 100%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Gravity

A

10ms^-2

or 9.8

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Work done equation

A

Work done = f x d
= force x distance

or work done = power x time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Acceleration

A

Vf - Vi
——- = a
time

20
Q

Velocity

A

v = displacement / time

= change in position / time

21
Q

Force

A

Force = Mass x acceleration

22
Q

Power

A

P = work done / time
= (force x distance) / time

or
P = E/t
= energy/time

23
Q

Current using Coulombs

A

I = Q/t
I is the current in amperes (amps), A
Q is the charge in coulombs, C
t is the time in seconds, s

24
Q

Units of

  • current
  • electric charge
  • time
  • voltage
  • energy
  • power
A 
Current: amps
Electric charge: coulombs
Time: seconds
Voltage: volts
Energy: Joules
Power: Watts
25
Q

Equation for resistance using potential difference and current

A 
Resistance = potential difference / current
R = p.d./I
26
Q

Calculate the combined resistance of two or more resistors in series

A

R total = R1 + R2

27
Q

Calculate resistance using voltage and current

A

R = V / I

28
Q

Gravity in Newtons

A

10Nkg^-1

29
Q

Moment equation

A

Moment = force x distance (perpendicular distance from the force to the pivot)
Moment in Newton metres
Force in Newtons
Distance in metres

30
Q

Electrical Power

A 
P = IV
P = I^2R
P = V^2 / R
P = E/t
31
Q

Electric Energy

A

E = IVt

32
Q

Specific Heat Capacity

A

The specific heat capacity of a substance is the amount of energy needed to change the temperature of 1 kg of the substance by 1°C.

E = m × c × θ
E is the energy transferred in joules, J
m is the mass of the substances in kg
c is the specific heat capacity in J / kg °C
θ (‘theta’) is the temperature change in degrees Celsius, °C

33
Q

Unbalanced force

A

F = ma

34
Q

Weight

A

W = mg

g = 10N/kg

35
Q

Wavelength

A

λ = v/f

λ= wavelength
v = speed
f = frequency
36
Q

Law of reflection

A

Angle of Incidence = Angle of reflection

37
Q

Electrical current

A 
I = Q / t
Q = coulomb of charge
t = time
38
Q

SulphIDE, sulphITE, and sulphATE

A 
Sulphide = S2-
Sulphite = SO3 ^2-
Sulphate = SO4 ^2-
39
Q

Power using force and velocity

A

P = Force x velocity

40
Q

Current

A 
I = q/t
I = V/r
41
Q

Voltage using energy in joules and coulombs

A

V = E/Q

42
Q

Torque

A

Torque = force x distance

43
Q

Refractive index

A

n = sin i / sin r

n = speed of light in air / speed of light in material

44
Q

Speed of light

A

3 x 10^8 m/s

45
Q

Frequency using the speed of light

A 
F = c/λ
λ = wavelength
c = fλ
v = fλ

where c = speed of light

46
Q

Units of frequency and wavelength

A

Frequency = Hz. Hertz

Wavelength in metres.

IGCSE Science (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions