Question

Given the typical grade of Pine Point ore as 3% for Pb, and 7% for Zn, with a sample weight of 13.6 kg, estimate the masses of Pb and Zn (in g) contained in the sample.

Select the correct expression for the mass of Pb in the sample:
a)
0.03
×
13.6
×
1000
0.03×13.6×1000
b)
0.03
×
13.6
×
10
0.03×13.6×10
c)
0.07
×
13.6
×
1000
0.07×13.6×1000
d)
0.07
×
13.6
×
10
0.07×13.6×10

Answer 1

The mass of lead (Pb) in the Pine Point ore sample is estimated using the expression '0.03×13.6×1000' and the mass of zinc (Zn) using '0.07×13.6×1000', both resulting in grams given a 13.6 kg sample.

Step-by-step explanation:

To estimate the masses of Pb (lead) and Zn (zinc) contained in the Pine Point ore sample weighing 13.6 kg with typical grades of 3% Pb and 7% Zn, we can use the following expressions:

• For Pb: mass of Pb in the sample = percentage of Pb × total sample weight in grams = 0.03 × 13.6 × 1000 (since there are 1000 grams in a kilogram).
• For Zn: mass of Zn in the sample = percentage of Zn × total sample weight in grams = 0.07 × 13.6 × 1000.

Therefore, the correct expression to calculate the mass of Pb in the sample is '0.03×13.6×1000'.