Explanation:
Percentage ethylene by weight = 57%
Percentage propylene by weight = 43%
Suppose in 100 grams of polymer:
Mass of ethylene = 57 g
Mass of propylene = 43 g
Moles of ethylene = 
Moles of propylene = 
1 mole =
molecules/ atoms
Units of ethylene = 
Units of propylene = 
a) Fraction of ethylene units:

b ) Fraction of propylene units:

Answer:
OPTION (A) : Testing a rock sample for gold content
Explanation:
For testing a rock sample of gold content you will need a Chemist. To test the material, the sample is rubbed on black stone which will leave a mark on the stone. This mark is tested by applying aqua fortis i.e nitric acid on the mark. If the mark gets dissolve then the material is not gold. If the mark sustain the it is further tested by applying aqua regia i.e nitric acid and hydrochloric acid which will prove the sample is of gold if it gets dissolve on using hydrochloric acid. The purity of the sample can be checked by differing the concentration of the aqua regia and comparing it with the gold material of the known purity.
382.85 Celsius is the temperature does 0.750 moles of an ideal gas occupy a volume of 35.9 L at 114 kPa.
Explanation:
Given data:
number of moles of the gas = 0.75 moles
volume of the gas = 35.9 liters
pressure of the gas = 114 KPa or 1.125 atm
R = 0.0821 latm/moleK
temperature of the gas T = ?
The equation used to calculate temperature from above data is ideal gas law equation.
the equation is :
PV = nRT
T = 
Putting the values in the above rewritten equation:
T = 
T = 655.9 K
To convert kelvin into celsius, formula used is
K = 273.15+ C
putting the values in the equation
C = 656 - 273.15
= 382.85 Celsius