Answer:
Explanation:
To calculate their average atomic masses which is otherwise known as the relative atomic mass, we simply multiply the given abundances of the atoms and the given atomic masses.
The abundace is the proportion or percentage or fraction by which each of the isotopes of an element occurs in nature.
This can be expressed below:
RAM = Σmₙαₙ
where mₙ is the mass of isotope n
αₙ is the abundance of isotope n
for this problem:
RAM of Li = m₆α₆ + m₇α₇
m₆ is mass of isotope Li-6
α₆ is the abundance of isotope Li-6
m₇ is mass of isotope Li-7
α₇ is the abundance of isotope Li-7
Answer:
C. 75%
Explanation:
From a heterozygous cross (Tt x Tt) the produced offspring would consist of:
- 25% TT -it would be tall-.
- 50% Tt -it would be tall as the gene T is dominant-.
- 25% tt -it would not be tall-.
Thus the produced offspring that would be tall is (50% + 25%) 75%. The answer is option C.
answer:
This allows us to tell alkenes apart from alkanes using a simple chemical test. Bromine water is an orange solution of bromine. It becomes colourless when it is shaken with an alkene. Alkenes can decolourise bromine water, but alkanes cannot.
explanation:
Answer:
a) 7.0.
b) Nickel sulfate hepta hydrate.
c) 280.83 g/mol.
d) 44.9%.
Explanation:
<u><em>a) What is the formula of the hydrate?</em></u>
The mass of the hydrated sample (NiSO₄.xH₂O) = 5.0 g,
The mass of the anhydrous salt (NiSO₄) = 2.755 g,
The mass of water = 5.0 g - 2.755 g = 2.245 g.
∴ no. of moles of water = mass/molar mass = (2.245 g)/(18.0 g/mol) = 0.1247 mol.
∴ no. of moles of anhydrous salt (NiSO₄) = mass/molar mass = (2.755 g)/(154.75 g/mol) = 0.0178 mol.
∴ water of crystallization in the sample (x) = no. of moles of water/no. of moles of anhydrous salt (NiSO₄) = (0.1247 mol)/(0.0178 mol) = 7.0.
<u><em>b) What is the full chemical name for the hydrate?</em></u>
The name of the salt (NiSO₄.7H₂O) is Nickel sulfate hepta hydrate.
<u><em>c) What is the molar mass of the hydrate? </em></u>
(NiSO₄.7H₂O)
The molar mass = molar mass of NiSO₄ + 7(molar mass of H₂O) = (154.75 g/mol) + 7(18.0 g/mol) = 280.83 g/mol.
<em><u>d) What is the mass % of water in the hydrate?</u></em>
The mass % of water = (mass of water)/(mass of hydrated sample) x 100 = (2.245 g)/(5.0 g) x 100 = 44.9%.
It is easiest to tell if a solution is saturated if there is residue on the bottom. If it crystallized, the solution is saturated. If it is a supersaturated solution, there will not be crystallization unless more of the solute is added, at which point all of it will crystallize.
