Answer:
They differ by their atomic mass and have same proton number.
Explanation:
Isotopes are atoms of the same element with the same proton or atomic number but with different atomic masses.
Answer: 0.13mol
Explanation:Please see attachment for explanation
The water will boil at C) 80°C
<h3>Further explanation</h3>
Given
Vapour pressure of water = 47 kPa
Required
Boiling point of water
Solution
We can use the Clausius-Clapeyron equation :

Vapour pressure of water at boiling point 100°C=101.325 kPa
ΔH vap for water at 100°C=40657 J/mol
R = 8.314 J/mol K
T₁=boiling point of water at 101.325 kPa = 100+273=373 K
Input given values :

Answer:
2.85moles of oxygen gas
Explanation:
Given parameters:
Volume of oxygen gas = 63.8L
Unknown:
Number of moles = ?
Solution:
We assume that the gas is under standard temperature and pressure. To find the number of moles, use the expression below:
1 mole of a gas at STP occupies a volume of 22.4L
So;
63.8L of oxygen gas will take up a volume of
= 2.85moles of oxygen gas
Iodine value is a measure of the degree of unsaturation in fats and oils. It is essentially the number of grams of iodine consumed by 100 g of fat. If the iodine number is in the range of 0-70 then it is a fat, any value above 70 is considered an oil.
Formula:
Iodine number = (ml of 0.1 N Thiosulphate blank- ml of 0.1N thiosulphate test) * 12.7 *100/1000* wt of sample
vol of thiosulphate required to titrate test sample (given oil) = 1 ml
wt of sample = 0.2 g
Information on the volume of thiosulphate required to titrate the blank solution is essential for calculation.
Iodine number = (X-1.0) * 12.7 * 100/1000* 0.2 = (X-1.0)*6.35