1) We know that rtp = number of moles × 24
= 0.25 × 24
= 6 dm³
Therefore the volume of 0.25 moles of gas at rtp is A) 6 dm³
3.1) Amount of Copper = 20 tonnes
Amount of pure copper from impure copper = 18 tonnes
Purity of copper = (Pure copper/ impure copper) × 100
= (18 / 20) × 100
= 18 × 5
= 90 %
Therefore the purity of copper is 90%
3.2) We know that oxygen has 8 protons and 8 neutrons, so the weight of oxygen molecule is 8 + 8 = 16 u
So, one mole of oxygen weighs 16 g, so 2 moles weigh 2 × 16 = 32 grams
But oxygen is diatomic so the weight is 32 × 2 = 64 grams
Therefore the weight of 2 moles of oxygen is 64 grams
3.3) Concentration of solution = Amount of solute/volume
= 4 moles/ 2 dm³
= 4 / 2
= 2 mol/dm³
Therefore the concentration of a solution containing 4 moles in 2 dm³ of solution is 2 mol/dm³
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Extremely sorry for the late answer
Answer:
The number following the name of the element is the number of subatomic particles inside the nucleus of the atom. This means that it is the mass number of the isotope. The average atomic mass of the element is the sum of the products of the percentage abundance and mass number of the naturally occurring isotopes.
Since, the average atomic mass of the hydrogen is nearest to 1 then, the most abundant isotope should be hydrogen-1.
The electronic configuration [the valence electrons is known by the last no after
