Mass is always conserved in a physical change. Energy may be released or absorbed when a substance changes from one physical state to another. In a chemical change, a chemical reaction yields a completely new substance. A substance's particles are changed during a chemical reaction.
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
Answer:
The pressure of the gas after getting compressed is 1.92 L.
Explanation:
To calculate the new pressure, we use the equation given by Boyle's law. This law states that pressure is directly proportional to the volume of the gas at constant temperature.
The equation given by this law is:
(At constant temperature)
where,
are initial pressure and volume.
are final pressure and volume.
We are given:
Putting values in above equation, we get:
The pressure of the gas after getting compressed is 1.92 L.
Answer:
4 hours and 30 minutes
Explanation: because first wave was 1:30:00 and the second is 1:34:30
1:30:00 goes into 1:34:30 4 hours and 30 minutes.
