Answer:
24.32
Explanation:
From the question given above, the following data were obtained:
Isotope A:
Mass of A = 24
Abundance (A%) = 78.70%
Isotope B
Mass of B = 25
Abundance (B%) = 10.13%
Isotope C:
Mass of C = 26
Abundance (C%) = 11.17%
Average atomic mass of Mg =..?
The average atomic mass of Mg can be obtained as illustrated below:
Average atomic mass = [(Mass of A × A%)/100] + [(Mass of B × B%)/100] + [(Mass of C × C%)/100]
Average atomic mass = [(24 × 78.70)/100] + [(25 × 10.13)/100] + [(26 × 11.17)/100]
= 18.888 + 2.5325 + 2.9042
= 24.3247 ≈ 24.32
Therefore, the average atomic mass of magnesium (Mg) is 24.32
The answer from this questions is the letter
B. He should not use his opinions as evidence.
Answer:
C
Explanation:
A negative deltaH means that the reaction has to give up heat in order to happen. You have to treat deltaH as a reactant. So the question is do you need to add heat to the reactants to make the products. If you do, deltaH is plus.
Heat is required to make a solid go to a gas. deltaH is plus. A is not the answer.
A lot of heat is required for B (something like 400 Kj / mole. Like A, deltaH is plus and B is not the answer.
C: The liquid has to give up heat in order for the this reaction to take place. C is the answer.
D requires heat. It is not the answer.
Answer:
Explanation:
Hello,
In this case, is possible to infer that the thermal equilibrium is governed by the following relationship:
Thus, both iron's and water's heat capacities are: 0.444 and 4.18 J/g°C respectively, so one solves for the mass of water as shown below:
Best regards.
Answer:
C) H2S
Explanation:
In chemistry, the dissolution of one substance in another is dependent on the magnitude of intermolecular interaction between the two substances. Hence, if two substances do not interact in one way or the other, then one can not dissolve the other.
Let us consider the fact that NH3 is a polar molecule and it is a general principle that like dissolves like. Hence, only H2S which is also a polar molecule can effectively interact with NH3 due to dipole-dipole interaction between the two molecules.
Also, ammonia reacts with hydrogen sulphide as follows;
2NH3 + H2S → (NH4)2S
Hence H2S is more likely to dissolve in NH3.
