Answer:
Pure water is a non conductor of electricity and dilute acids in their aqueous solutions form free ions, which conducts electricity. Thus when we need to electrolyse water, a dilute acid is added to increase its conductivity.
Possible answer could be 900 or 450.
Answer:
108 kPa
Step-by-step explanation:
To solve this problem, we can use the <em>Combined Gas Laws</em>:
p₁V₁/T₁ = p₂V₂/T₂ Multiply each side by T₁
p₁V₁ = p₂V₂ × T₁/T₂ Divide each side by V₁
p₁ = p₂ × V₂/V₁ × T₁/T₂
Data:
p₁ = ?; V₁ = 34.3 L; T₁ = 31.5 °C
p₂ = 122.2 kPa; V₂ = 29.2 L; T₂ = 21.0 °C
Calculations:
(a) Convert temperatures to <em>kelvins
</em>
T₁ = (31.5 + 273.15) K = 304.65 K
T₂ = (21.0 + 273.15) K = 294.15 K
(b) Calculate the <em>pressure
</em>
p₁ = 122.2 kPa × (29.2/34.3) × (304.65/294.15)
= 122.2 kPa × 0.8542 × 1.0357
= 108 kPa
Answer:
The time taken for the cross mark to disappear decreases steadily down the column.
Explanation:
Now if we look at the data provided, we will discover that the volume of the HCl was held constant while the volume of the thiosulphate was increased steadily and the volume of water decreased steadily.
Recall that a system is more concentrated when it contains less volume of water and more volume of reactants. Hence as the volume of water in the system is being reduced, the concentration of reactants is increased.
It has been established that an increase in the concentration of reactants lead to an increase in the rate of reaction. The disappearance of the cross shows the completion of the reaction between HCl and thiosulphate. The faster or slower the cross disappears, the faster or slower the rate of reaction.
Since increase in concentration of reactants increases the rate of reaction, it is observed that as the volume of the thiosulphate increases (reactant concentration increases) the cross disappears faster (rate of reactant increases). Hence as the volume of thiosulphate increases, it takes a shorter time for the cross to disappear. This implies that the time column in the table (refer to the question) will decrease steadily as the volume of thiosulphate increases.
