Answer:
When the volume of product increases.
When the weight of the product decreases.
Option (a) and (d) are correct.
Explanation:
The overall density of the product can be decreased:
a. Increase the volume of the product (and keep the material same)
d. Decrease the weight of the product ( and keep the same material ).
Density is calculated as the ratio of mass to the volume.
Density is inversely related to volume and directly related to mass.
So, when the mass of the product is increased then the density will increase keeping the material same. Density will also increase when the volume of the product decreased.
Mass = mr x moles
Mr of CuCl2 = ( 63.5) + ( 35.5 x 2) = 134.5
2.5 = 134.5 x moles
2.5 / 134.5 = moles
Moles = 0.019 (2DP)
0.25g of Al
Mr of Al = 27
0.25 = 27 x moles
0.25/ 27 = 0.0093 moles (2sf)
Hope this helps :)
I think the answer is D no change. Though you add more CO2, but the pressure is not mentioned. If the pressure is constant and the reaction is already balanced, the H2O is also saturation and can not absorb more CO2.
So half life is the time taken for a sample to decay to half its original mass, its a constant and applies to any original mass, it could be 5g or 1kg, it will take the same amount of time for the original mass to half. In this case the half life is 3 days.
After 3 days the sample will be at half its original mass, now 50g.
Now we can treat the 50g as if its a new sample. After another 3 days (6 days in total) there will be half of 50g left, = 25g.
