Answer:
A. wool, silkworm, cocoon, and cellulose
Explanation:
I hope this helped!
Answer is: volume of sodium hydroxide is 500 cm³.
Chemical reaction: H₂S + 2NaOH → Na₂S + 2H₂O.
From chemical reaction: n(H₂S) : n(NaOH) = 1 : 2.
n(NaOH) = 2 ·0.050 mol.
n(NaOH) = 0.1 mol.
V(NaOH) = n(NaOH) ÷ c(NaOH).
V(NaOH) = 0.1 mol ÷ 0.2 mol/dm³.
V(NaOH) = 0.5 dm³.
V(NaOH) = 0.5 dm³ · 1000 cm³/dm³.
V(NaOH) = 500 cm³.
First we will calculate the number of moles of Iron:
, where n is the number of moles, m is the mass of iron in the reaction and M is the Atomic weight.
moles of Iron.
The same number of moles of Oxygen will take part in the reaction.
So
where 32 is the Atomical Weight of Oxygen (16 x 2).
=>
g
The trick for this problem is to understand atomic mass: the fact that different atoms have different masses. What we need to do is add up all the atomic masses of the compound and work out the ratio of mass of water to the mass of sodium carbonate. Atomic masses are often given for each atom in the periodic table, but you can look them up on google too.
You can do this by adding up individual atoms for each molecule, or you can shortcut and lookup the molar mass of the compound (i.e.the task already done for you).
The molar mass of water is 18.01g/mole so for 10 moles of water we have a mass of 180.1g.
The molar mass of sodium carbonate is 106g/mole (google).
So the total mass of the sodium carbonate decahydrate compound is 180.1+106 = 286.1g, of which water would make up 180.1g, so the percentage of water is is 180.1/286.1 = 0.629, so we can round this to 63%
:)
Answer;
The total pressure is 1.107 atm.
Explanation;
The total pressure is the sum of the pressures of the three gases in the flask
Pressure (total) = 0.215 atm + 0.066 atm + 0.826 atm = 1.107 atm
= 1.107 atm.
