Answer: 72 grams of
are needed to completely burn 19.7 g 
Explanation:
According to avogadro's law, 1 mole of every substance weighs equal to molecular mass and contains avogadro's number
of particles.
To calculate the number of moles, we use the equation:

Putting in the values we get:


According to stoichiometry:
1 mole of
requires 5 moles of oxygen
0.45 moles of
require=
moles of oxygen
Mass of 
72 grams of
are needed to completely burn 19.7 g 
Answer:
See explanation
Explanation:
Light is a form of energy. Both ultraviolet light and xrays are part of the electromagnetic spectrum.
As was said in the question, ultraviolet rays is absorbed by the rubber. We must know that prolonged exposure of this piece of rubber to incident ultraviolet light causes the vaporization of volatile materials in the rubber.
When volatile materials in the rubber vaporize, the rubber can become solid. Thus, ultraviolet light can cause rubber to become solid.
However, not all types of light can do this hence it does matter the type of light that falls on the rubber material.
Answer:
The percentage deviation is
%
Explanation:
From the question we are told that
The concentration is of the solution is 
The true absorbance A = 0.7526
The percentage of transmittance due to stray light
% 
Generally Absorbance is mathematically represented as

Where T is the percentage of true transmittance
Substituting value



%
The Apparent absorbance is mathematically represented

Substituting values


= 0.7385
The percentage by which apparent absorbance deviates from known absorbance is mathematically evaluated as


%
Since Absorbance varies directly with concentration the percentage deviation of the apparent concentration from know concentration is
%
Answer:
The answer to your question is: 65.9 g released of CO2
Explanation:
MW CO2 = 44 g
MW CuCO3 = 123.5 g
CO2 released = ?
CuCO3 = 185 g
CuCO3 ⇒ CO2 + CuO
123.5 ----------- 44g
185 g ----------- x
x = (185 x 44) / 123.5
x = 65.9 g released of CO2