Answer: bạn viết phương trình Phenol + NaOH
=> nNaOH = nPhenol = 0,2 mol
m Phenol = 0,2x94 = 18,8 gam
%mPhenol = 18,8/28,9% = 65,05
Explanation:
Answer:
252.5g
Explanation:
Given parameters:
Volume of vodka = 0.8L
Molarity of ethanol = 6.86M
Unknown:
Mass of ethanol = ?
Solution:
Molarity is one of the ways of expressing concentration. It is the number of moles of a substance in a solution.
Since Vodka = ethanol + water = solution
Molarity = 
Number of moles of ethanol = molarity of vodka x volume of solution
Once we obtain the number of moles, we can derive the mass of the ethanol;
Number of moles = 6.86M x 0.8L = 5.49moles
Mass of ethanol = number of moles x molar mass
molar mass of ethanol = 12 + 3(1) + 12 + 2(1) + 16 + 1 = 46g/mol
Mass of ethanol = 5.49 x 46 = 252.5g
What are <span>stoichiometry equations?</span>
All you have to do is multiply the amount of moles by 6.02x10^23 which is Avagadro's number.
Answer:
9.3 × 10²³ molecules
Explanation:
Given data:
Mass of methane = 24.7 g
Number of molecules = ?
Solution:
The given problem will solve by using Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.
The number 6.022 × 10²³ is called Avogadro number.
For example,
18 g of water = 1 mole = 6.022 × 10²³ molecules of water
For 24.7 g methane:
Number of moles = mass/ molar mass
Number of moles = 24.7 g/ 16.04 g/mol
Number of moles = 1.54 mol
1 mole = 6.022 × 10²³ molecules
1.54 × 6.022 × 10²³ molecules
9.3 × 10²³ molecules
