Answer:
D. 0.543kg of copper metal is produced from 0.680kg of copper 1 sulphide.
Explanation:
First write the equation for the reaction:
Cu2S + O2 ------> 2Cu + SO2
Determine the mole ratio of the two substances:
I mole of Cu2O forms 2 moles of Copper metal
The number of moles of copper 1 sulphide used is;
n = mass of Cu2S / molar mass of Cu2S
Mass = 0.680kg = 680g
Molar mass = 159.16g/mol
n = 680g / 159.16g/mol
n = 4.272moles
Determine the number of mole of copper:
Number of moles of copper metal produced from 4.272moles of copper 1 sulphide is therefore:
n of copper = 2 * 4.272 Moles
n = 8.544moles.
Determine the mass copper:
The mass of copper metal produced is therefore = number of moles of copper * molar mass of copper
mass = 8.544 moles * 63.55g/mol
mass = 542.97grams
Mass = 0.543kg
The moles of CaCO3 which are there in antacid tablet that contain 0.515g CaCO3 is calculated as follows
moles =mass/molar mass
the molar mass of CaCO3 = ( 40 x1)+ (12 x 1) + (16 x 3)= 100 g/mol
moles is therefore= 0.515g/100 g/mol= 5.15 x10^-3 moles
Answer:

Explanation:
Hello!
In this case, since the relationship between molecules and mass is first analyzed via the Avogadro's number to compute the moles in the given molecules:

We now use the molar mass of carbon tetrachloride (153.81 g/mol) to obtain the required grams:

Best regards!