Answer:
A..?
Explanation:
Im not entirely sure you should get a 2nd opinion M8.
Stoichiometry is “quantitative relationship” among the “reactants” and the “products” in a “chemical reaction”.
<u>Explanation</u>:
In stoichiometry “stoicheion” means element and “metron” means measure in Greek. The stoichiometric calculation depends upon “stoichiometric coefficients” in a “chemical equation” which can be explained as the “number of moles” of each substance (reactants or products). Stoichiometric calculation is done as follows:
For example reaction between nitrogen and hydrogen to form ammonia as
Here stoichiometric coefficients show that “one molecule of nitrogen” reacts with “three molecules of hydrogen” to form “two molecules of ammonia”. Multiplying Avogadro number 
to no of molecules in equation:
Taking molar masses into consideration:
Hence balanced equation gives stoichiometric coefficients which gives proportion by moles.
<span>The number of atoms in 4.75 moles of gold (Au) is found using Avogadro's number, which is 6.022Ă—1023 mol-1. Determine the number of atoms by multiplying 4.75 moles by Avogadro's number. The number of atoms in 4.75 moles of gold is 2.8605172125000205e24.</span>
Answer:
23.46 mmHg is the vapor pressure for the solution
Explanation:
To solve this problem we need to apply a colligative property, which is the lowering vapor pressure.
The formula for this is: P°- P' = P° . Xm
where P' is vapor pressure for solution and P°, vapor pressure for pure solvent.
Let's determine the Xm (mole fraction for solute)
We calculate the moles of the solute and the solvent and we sum each other:
Moles of solute: 60 g /342 g/mol = 0.175 moles of sucrose
Moles of solvent: 250 g / 18 g/mol = 13.8 moles of water
Total moles: 13.8 moles + 0.175 moles = 13.975 moles
Xm for solute: 0.175 moles / 13.975 moles = 0.0125
Let's replace data in the formula: 23.76 mmHg - P' = 23.76 mmHg . 0.0125
P' = - (23.76 mmHg . 0.0125 - 23.76 mmHg) → 23.46 mmHg
