All four answers are right 100%.
Answer:
92.01 g/mol
Explanation:
So first you need to find the empirical formula by the percents. That would be, assuming that you have 100 grams of the the sample, divide each quantity of each element found by its respective molar mass.
30.4 g of N ÷ 14 g/mol N= 2.17 mol of N
69.6 g of O ÷ 16g/mol= 4.35 mol of O
You can establish now the empirical formula.
N2.17O4.35,
but since you can't have a decimal subscript, you divide each subscript by the minimum subscript
NO2
So then you're said that the molecular formula derived from that empirical formula has 2 nitrogen, so you multiply all the subscripts, by 2:
N2O4
-Dinitrogen Tetraoxide
-Nitrogen oxide (IV)
Then all you have to do is find the molecular mass of the compound using the periodic table and what you obtain is the molar mass.
remember: molecular mass is correspondent to molar mass.
Answer:
Calculate the number of moles of CO2 by the formula n=PV/RT, where P is the pressure from Step 3, V is the volume from Step 2, T is the temperature from Step 1 and R is a proportionality constant equal to 0.0821 L atm / K mol.
Explanation:
mass of pentane : = 30.303 g
moles of Al₂(CO₃)₃ : = 0.147
<h3>Further explanation</h3>
Given
1. Reaction
C₅H₁₂+8O₂→6H₂O+5CO₂.
45.3 g water
2. 2AlCl₃ + 3MgCO₃ → Al₂(CO₃)₃ + 3MgCl₂
37.2 MgCO₃
Required
mass of pentane
moles of Al₂(CO₃)₃
Solution
1. mol water = 45.3 : 18 g/mol = 2.52
From equation, mol ratio of C₅H₁₂ : H₂O = 1 : 6, so mol pentane :
= 1/6 x mol H₂O
= 1/6 x 2.52
= 0.42
Mass pentane :
= mol x MW
= 0.42 x 72.15 g/mol
= 30.303 g
2. mol MgCO₃ : 37.2 : 84,3139 g/mol = 0.44
mol Al₂(CO₃)₃ :
= 1/3 x mol MgCO₃
= 1/3 x 0.44
= 0.147
The number of moles of Neon gas : 1.079
<h3>Further explanation</h3>
Given
24.18 Liters of Neon gas at STP
Required
The number of moles
Solution
There are 2 conditions that are usually used as a reference in chemical calculations (mainly for determining the volume per mole of a gas or the molar volume), STP and RTP
Conditions at T 0 ° C and P 1 atm are stated by STP (Standard Temperature and Pressure). At STP, Vm is 22.4 liters / mol.
So mol for 24.18 L :
= 24.18 : 22.4
= 1.079 moles
