Explanation:
a) Using the provided information about the density of gold, the sample size, thickness, and the following equations and comersion factors, find the area of the gold leaf:

Gold 

First, find the volume of the sample and then find the area of the sample.


b. Using the provided information from part
), the radius of the cylinder, and the following equation for the volume of a cylinder, find the length of the fiber :


The wall would absorb extra heat during the day when the sun is out, then release the heat back into the room when the sun goes down.
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Answer:</h3>
B. 0.33 mol
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Explanation:</h3>
We are given;
Gauge pressure, P = 61 kPa (but 1 atm = 101.325 kPa)
= 0.602 atm
Volume, V = 5.2 liters
Temperature, T = 32°C, but K = °C + 273.15
thus, T = 305.15 K
We are required to determine the number of moles of air.
We are going to use the concept of ideal gas equation.
- According to the ideal gas equation, PV = nRT, where P is the pressure, V is the volume, R is the ideal gas constant, (0.082057 L.atm mol.K, n is the number of moles and T is the absolute temperature.
- Therefore, to find the number of moles we replace the variables in the equation.
- Note that the total ball pressure will be given by the sum of atmospheric pressure and the gauge
- Therefore;
- Total pressure = Atmospheric pressure + Gauge pressure
We know atmospheric pressure is 101.325 kPa or 1 atm
Total ball pressure = 1 atm + 0.602 atm
= 1.602 atm
That is;
PV = nRT
n = PV ÷ RT
therefore;
n = (1.602 atm× 5.2 L) ÷ (0.082057 × 305.15 K)
= 0.3326 moles
= 0.33 moles
Therefore, there are 0.33 moles of air in the ball.
Answer:
Hydrogen peroxide should be stored in
1) a cool environment
2) with amber bottles away from sunlight
3) with little drops of sodium phosphate
Explanation:
It has been confirmed that heat and light aids in the decomposition of hydrogen peroxide according to the equation; 2H2O2→2 H2O + O2.
This means that hydrogen peroxide must be stored in a cool place. This will reduce its rate of decomposition. Secondly, it should be stored in amber bottles away from light since light also aids in its decomposition.
Thirdly, drops of sodium phosphate may be added to prevent its catalytic decomposition during storage.
Answer:
The concentration is 0,2925M
Explanation:
We use the formula
C initial x V initial = C final x V final
11,7 M x 25 ml = C final x 1000 ml
C final= (11,7 M x 25 ml)/1000 ml = 0, 2925 M
(This formula applies to liquid solutions)