Answer: The vapor pressure of water at 10°C will be less as compared with its vapor pressure at 50°C.
Explanation:
Vapor pressure of a liquid is defined as the pressure exerted by the vapors in equilibrium with the liquid/solution at a particular temperature.
As Kinetic energy is dependent on the absolute temperature of the gas.

where R = gas constant
T = temperature
On increase in temperature, the kinetic energy of the molecules increase and thus more liquid molecules can escape to form vapours and thus will exert more vapor pressure.
Thus the vapor pressure of water at 10°C will be less as compared with its vapor pressure at 50°C.
Answer:
a) Approximate boiling point of HBr = -60.15 °C
b) Approximate boiling point of AsH₃ = -52.25 °C
Explanation:
Döbereiner stated that some elements could be arranged in groups of 3 similar elements ( known as "triads) , and the element of the middle ( elements are ordered with respect to their atomic mass) would have properties between the other 2 ( the average value)
a) In the first case the triad would be the halogen triad ( Cl , Br and I ) . And according to Döbereiner , the boiling point of HBr should be the average of HCl and HI . Therefore
Approximate boiling point of HBr = [(- 84.9°C) + (-35.4°C)]/2 = -60.15 °C
b) Simmilarly for AsH₃ , PH₃ and SbH₃ , the boiling point of AsH₃ would be
Approximate boiling point of AsH₃ = [(- 87.4°C) + (-17.1°C)]/2 = -52.25 °C
The answers from top to bottom right to left are
3,1,2,4
Copper wire is not an example of a pure element because although it's made by pure elements, it's not one itself. It's made by factories.
Have a nice day! :)