Answer:
6.8g of solute are needed
Explanation:
Percent by mass, (w/w%) is defined as the mass of solute in 100g of solution. A solution that is 3.4% contains 3.4g of solute in 100g of solution. That means to make 200g of solution are required:
200g solution * (3.4g solute / 100g solution) = 6.8g of solute are needed
Moles of Na2SO4 = conc. x volume(dm3)
= 2 x (2500cm3/1000)
= 5 mol
Mass of Na2SO4 = moles x molar mass
= 5 x ((23 x 2) + 32.1 + (16 x 4))
= 710.5g
Answer:
Giving away protons to the water molecules
Explanation:
When acids are mixed with water the following reaction takes place:
H^+(aq) + H2O(l) ------> H3O^+(aq)
Hence when acids are added to water, acids donate a proton to water to form the oxonium ion H3O^+ by coordinate covalent bonding. Note that acids contain the hydrogen ion H^+
Answer:
677.7 mmHg
Explanation:
The first empirical study on the behaviour of a mixture of gases was carried out by John Dalton. He established the effects of mixing gases at different pressures in the same vessel.
Dalton's law states that,the total pressure exerted by a mixture of gases is equal to the sum of the partial pressures of the individual gases present in the mixture of gases. When a gas is collected over water, the gas also contains some water vapour. The partial pressure of the gas will now be given as; total pressure of gas mixture - saturated vapour pressure of water (SVP) at that temperature.
Given that;
Total pressure of gas mixture = 692.2 mmHg
SVP of water at 17°C = 14.5 mmHg
Therefore, partial pressure of oxygen = 692.2-14.5
Partial pressure of oxygen = 677.7 mmHg
