Answer:
50
Explanation:
We will need a balanced equation with masses, moles, and molar masses of the compounds involved.
1. Gather all the information in one place with molar masses above the formulas and masses below them.
Mᵣ: 30.01 32.00 46.01
2NO + O₂ ⟶ 2NO₂
Mass/g: 80.00 16.00
2. Calculate the moles of each reactant

3. Calculate the moles of NO₂ we can obtain from each reactant
From NO:
The molar ratio is 2 mol NO₂:2 mol NO

From O₂:
The molar ratio is 2 mol NO₂:1 mol O₂

4. Identify the limiting and excess reactants
The limiting reactant is O₂ because it gives the smaller amount of NO₂.
The excess reactant is NO.
5. Mass of excess reactant
(a) Moles of NO reacted
The molar ratio is 2 mol NO:1 mol O₂

(b) Mass of NO reacted

(c) Mass of NO remaining
Mass remaining = original mass – mass reacted = (80.00 - 30.01) g = 50 g NO
Option D
Step by step explanation:
Answer:
43.13Kg of melamine
Explanation:
The problem gives you the mass of urea and two balanced equations:

First we need to calculate the number of moles of urea that are used in the reaction, so:
molar mass of urea = 
The problem says that you have 161.2Kg of urea, so you take that mass of urea and find the moles of urea:
161.2Kg of urea
2684 moles of urea
Now from the stoichiometry you have:
2684 moles of urea
= 447 moles of melamine
The molar mass of the melamine is
so we have:
= 5637.64 g of melamine
Converting that mass of melamine to Kg:
5637.64 g of melamine *
= 56.38 Kg of melamine, that is the theoretical yield of melamine.
Finally we need to calculate the mass of melamine with a yield of 76.5%, so we have:
%yield = 100*(Actual yield of melamine / Theoretical yield of melamine)
Actual yield of melamine =
= 43.13Kg of melamine
Answer:
<h2>4</h2>
Explanation:
The pH of a solution can be found by using the formula
![pH = - log [ {H}^{+} ]](https://tex.z-dn.net/?f=pH%20%3D%20-%20log%20%5B%20%7BH%7D%5E%7B%2B%7D%20%5D)
From the question we have

We have the final answer as
4
Hope this helps you