Answer:
14.5 g silver
Explanation:
This is a problem using the stoichiometry of the reaction. First thing we need is the balanced equation:
Zn + 2 AgNO3 ----------------------- 2 Ag + Zn(NO3)2
We know that 14.6 g of Zn did not reacted, then we can calculate the amount of Zn reacted and do the calculation given the above reaction.
amount Zn reacted: 19.0 -14.6 g Zn = 4.4 g Zn
atomic weight of Zn: 65.37 g/mol
mol Zn reacted: 4.4 g Zn x ( 1 mol Zn/ 65.37 g Zn) = 0.067 mol Zn
We know from the balanced equation that moles of Ag are produced from 1 mol Zn therefore the mol of Ag produced are:
0.067 mol Zn x 2 mol Ag/ 1mol Zn = 0.135 mol Ag
and the mass of silver then will be given by multiplying by the atomic weight of silver:
0.135 mol Ag x 107.9 g/mol = 14.5 g Ag
Answer:
(a) The coefficient of performance of an irreversible refrigeration cycle is always less than the coefficient of performance of a reversible refrigeration cycle when both exchange energy by heat transfer with the same two reservoirs.
Explanation:
According to the Kelvin–Planck statement of the second law of thermodynamics ,it is not possible to construct a device which operates in cycle and does not produce effect on the environment than the production of work.
We know that
Coefficient of performance is the ratio of desired effect to the work input in a cycle.
Given all option is correct but most appropriate option is a.
So the option a is correct
(a) The coefficient of performance of an irreversible refrigeration cycle is always less than the coefficient of performance of a reversible refrigeration cycle when both exchange energy by heat transfer with the same two reservoirs.
Answer:
Color change
Explanation:
If it is a chemical change, then the color will change. Sometimes chemical changes also cause fizzing and bubbling.
