a substance has a vapor pressure of 0.2020 atm at 261.5 k. if its heat of vaporization is 20.94 kj/mol, calculate its vapor pres
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Answer: 0.9375 g
Explanation:
To calculate the number of moles for given molarity, we use the equation:
.....(1)
Molarity of solution = 0.75 M
Volume of solution = 25.0 mL = 0.025 L
Putting values in equation 1, we get:
According to stoichiometry :
2 moles of require = 1 mole of
Thus 0.01875 moles of will require=
of
Mass of
Thus 0.9375 g of is required to react with 25.0 ml of 0.75 M HCl
Taking into account the reaction stoichiometry, 2.13 grams of magnesium was dissolved in the solution.
<h3>Reaction stoichiometry</h3>In first place, the balanced reaction is:
Mg²⁺(aq) + Na₂CO₃(aq) → MgCO₃(s) + 2 Na⁺(aq)
By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of moles of each compound participate in the reaction:
- Mg²⁺: 1 mole
- Na₂CO₃: 1 mole
- MgCO₃: 1 mole
- Na⁺: 2 moles
The molar mass of the compounds is:
- Mg²⁺: 24.3 g/mole
- Na₂CO₃: 106 g/mole
- MgCO₃: 84.3 g/mole
- Na⁺: 23 g/mole
Then, by reaction stoichiometry, the following mass quantities of each compound participate in the reaction:
- Mg²⁺: 1 mole ×24.3 g/mole= 24.3 grams
- Na₂CO₃: 1 mole ×106 g/mole= 106 grams
- MgCO₃: 1 mole ×84.3 g/mole=84.3 grams
- Na⁺: 2 moles ×23 g/mole= 46 grams
The following rule of three can be applied: If by reaction stoichiometry 1 mole of Na₂CO₃ react with 24.3 grams of magnesium, 0.0877 moles of Na₂CO₃ react with how much mass of magnesium?
<u><em>mass of magnesium= 2.13 grams</em></u>
Finally, 2.13 grams of magnesium was dissolved in the solution.
Learn more about the reaction stoichiometry:
<u>Answer:</u> The limiting reagent in the reaction is bromine.
<u>Explanation:</u>
Limiting reagent is defined as the reagent which is completely consumed in the reaction and limits the formation of the product.
Excess reagent is defined as the reagent which is left behind after the completion of the reaction.
Given values:
Moles of iron = 10.0 moles
Moles of bromine = 12.0 moles
The chemical equation for the reaction of iron and bromine follows:
By the stoichiometry of the reaction:
If 3 moles of bromine reacts with 2 moles of iron
So, 12.0 moles of bromine will react with = of iron
As the given amount of iron is more than the required amount. Thus, it is present in excess and is considered as an excess reagent.
Hence, bromine is considered a limiting reagent because it limits the formation of the product.
Thus, the limiting reagent in the reaction is bromine.