- #1
Maxwell Kraft
- 6
- 0
Hello. I just started a first year chemistry course after switching to the sciences from the arts, and wanted to double-check some equations with you because this is a little new to me. I'm good with the qualitative stuff, but the quantitative parts come a little harder.
Q1: A sheet of metal is 93.3 mm wide and 40.6 mm long. If it weighs 4.877 g and the density of the metal is 1.74 g/cm3, what is the thickness of the sheet (in mm)?
My answer: 4.877g / 1.74g/cm^3 = 2.80cm^3
93.3mm x 40.6mm = 3780mm (3 sig figures)
2.80cm^3 / 3780mm = 0.740mm
93.3mm x 40.6mm x 0.740mm = 2.80cm^3
Thus, the sheet is 0.740mm thick.
Q2: If PV = [gR(T+273.15)]/M, solve for M when P = 334, V = 0.350, g = 0.274, R = 62.37, and T = 39.
My answer:
PV = [gR(T+273.15)] / M
(334)(0.350) = (0.274) (62.37) (312.15) / M
116 = 5330 (3 sig figures) / M
116 / 5330 = M
0.0217 = M
Q3: An ore contains 42.3 % of the mineral ilmenite, FeTiO3, which is a source of the element Ti. How much ore must be processed in order to obtain 41.0 kg of Ti?
Molar masses
Fe = 55.85g
Ti = 2004.4g
O = 16.00g x 3 = 48.00g
total = 308.2g
308.2g / 204.4g = 1.50
41.0kg x 1.50 = 61.5kg
100 / 42.3 = 2.36
61.5 x 2.36 = 145 kg of ore are needed to obtain 41.0kg of thallium.
Thank you all in advance.
M.
Q1: A sheet of metal is 93.3 mm wide and 40.6 mm long. If it weighs 4.877 g and the density of the metal is 1.74 g/cm3, what is the thickness of the sheet (in mm)?
My answer: 4.877g / 1.74g/cm^3 = 2.80cm^3
93.3mm x 40.6mm = 3780mm (3 sig figures)
2.80cm^3 / 3780mm = 0.740mm
93.3mm x 40.6mm x 0.740mm = 2.80cm^3
Thus, the sheet is 0.740mm thick.
Q2: If PV = [gR(T+273.15)]/M, solve for M when P = 334, V = 0.350, g = 0.274, R = 62.37, and T = 39.
My answer:
PV = [gR(T+273.15)] / M
(334)(0.350) = (0.274) (62.37) (312.15) / M
116 = 5330 (3 sig figures) / M
116 / 5330 = M
0.0217 = M
Q3: An ore contains 42.3 % of the mineral ilmenite, FeTiO3, which is a source of the element Ti. How much ore must be processed in order to obtain 41.0 kg of Ti?
Molar masses
Fe = 55.85g
Ti = 2004.4g
O = 16.00g x 3 = 48.00g
total = 308.2g
308.2g / 204.4g = 1.50
41.0kg x 1.50 = 61.5kg
100 / 42.3 = 2.36
61.5 x 2.36 = 145 kg of ore are needed to obtain 41.0kg of thallium.
Thank you all in advance.
M.