Answer: 15.3 grams C
Explanation: 1 mole is 6.02x10^23 atoms. We can find the moles of C in 7.675 x 10^23 atoms of C by dividing:
(7.675 x 10^23 atoms C)/(6.02x10^23 atoms C/mole) = 1.275 moles C
The molar mass of carbon is 12g/mole. So the mass of 7.675 x 10^23 atoms is (1.275 moles C)*(12 g/mole C) = 15.3 grams.
Answer:
Only gives spontaneous reaction.
Explanation:
A redox reaction will be spontaneous if standard reduction potential () of the reaction is positive. Because it leads to negative standard gibbs free energy change (), which is a thermodynamic condition for spontaneity of a reaction.
Where and represents standard reduction potential of reduction half cell and standard reduction potential of oxidation half cell.
(1) Oxidation: ;
Reduction: ;
So,
Hence this pair will give spontaneous reaction.
(2) Similarly as above,
Hence this pair will give non-spontaneous reaction.
(3) Similarly as above,
Hence this pair will give non-spontaneous reaction.
(4) Similarly as above,
Hence this pair will give non-spontaneous reaction.
The correct answer is (4)
Evaporation or vaporization is a change of phase of a substance from liquid to gas (vapor).
For water, this process requires the addition of 2260 Joules of heat energy for every gram of water that evaporates (vaporizes). The added energy remains in the water vapor (potential energy) and will be released in the process of condensation.
This heat energy that is required to change water into vapor is called the latent heat of vaporization.
Latent heat of a material is defined as the energy required to change the state of a material without changing the material's temperature.
The solubility of the borax will increase as the temperature increase.