What Are The Number Of Significant Figures In Chemistry

Measurement in Chemistry Assignment, Due 22 March, Surname A-D

Instructions: All questions must have the correct units and correct number of significant figures. Show all calculations and carry the units throughout. Submit your answers on a new page. Include your name and student number.

Q1. Report the number of significant figures in each of the following: a. 0.20 b. 9.05 c. 164300 (1 mark)

Q2. Report each of the following measurements using both the scientific notation and metric prefix systems: a. 345 m b. 0.0805 g c. 4650000 N (2 marks)

Q3. Determine the density (in g/cm3) of a solid given;
A beaker was weighed at 155 g then 940.0 cm3 of solid was added and the new weight was 713 g.
(2 marks)

Q4. Report the answer to the following: 65.9 - (12 + 8.51) = ? (2 marks)

Q5. The Specific Heat of a substance is the energy (Joules) required to raise one gram of substance by one degree celsius, (units: J/goC)
Heating 95.5 mL of a liquid from 18.5 oC to 47.9 oC takes 10515 J of energy. The density of the liquid at 18.5 oC is 1.210 g/mL.
What is the Specific Heat of this liquid in this experiment?

(3
marks)

V.Cumner :1068138
Q1.
a. 0.20 (2sf) b. 9.05 (3sf) c. 164300 (4sf)

Q2.

Measurement scientific notation metric prefix sig/figs a. 345m 3.45 x [pic]m 345m 3sf b. 0.0805g 8.05 x [pic]g 80.5kg 3sf c.4650000N 4.65 x [pic]N 4.65MN 3sf

Q3.

Mass beaker + substance 713g - (unit place)
- Mass of beaker 155g (unit place)
Mass of substance = 558g (unit place)

Volume = 940.0[pic]

558g_____(3sf) 940.0[pic] (4sf) = 0.593617[pic]

=0.593[pic] (3sf)

=5.93 x[pic][pic](3sf)

Q4.

65.9 – (12+8.51)
12(unit place) +8.51(2dp) = 20.51 (really unit place)
65.9 (1dp) – 20.51(really unit place) = 45.39

= 45 (unit place)

Q5.

Specific Heat (Cp) = ____________10515 J___________________ (95.5mL -:- 1.210g/mL) x (47.9[pic] - 18.5[pic])

[pic](1dp) 95.5mL(3sf) -[pic] (1dp) 1.210g/mL(4sf) = 78.925616g(3sf) [pic](1dp)

_ 10515 J_(5sf)_______
78.925616g (really3sf) x 29.4[pic](3sf)

10515 J____ (5sf)
2320.4131g/[pic]C (really 3sf)
= 4.5315207 J/g[pic]C
Cp = 4.53 J/g[pic]C (3sf)