Class 11th

The photoelectric current from Na (work function, w? = 2.3eV) is stopped by the output voltage of the cell
Pt(s)/H?(g, 1 bar) | HCl (aq., pH = 1)|AgCl(s)|Ag(s).
The pH of aq. HCl required to stop the photoelectric current from K(w? = 2.25 eV), all other conditions remaining the same, is * 10?² (to the nearest integer).
Given,
2.303(RT/F) = 0.06 V; E°(AgCl|Ag|Cl?) = 0.22 V

The volume strength of 8.9M H?O? solution calculated at 273 K and 1 atm is (R = 0.0821 Latm K?¹ mol?¹) (rounded off to the nearest integer)
(p-block)

Which of the following compounds produces an optically inactive compound on hydrogenation?

Consider a completely full cylindrical water tank of height 1.6 m and cross-sectional area 0.5 m². It has a small hole in its side at a height 90 cm from the bottom. Assume, the cross-sectional area of the hole to be negligibly small as compared to that of the water tank. If a load 50 kg is applied at the top surface of the water in the tank then the velocity of the water coming out at the instant when the hole is opened is : (g = 10 m/s²)

If the boiling point of H?O is 373 K, the boiling point of H?S will be:

A bakelite beaker has volume capacity of 500cc at 30°C. When it is partially filled with V? volume (at 30°C) of mercury, it is found that the unfilled volume of the beaker remains constant as temperature is varied. If γ(beaker) = 6 × 10? °C?¹ and γ(mercury) = 1.5 × 10? °C?¹, where γ is the coefficient of volume expansion, then V? (in cc) is close to
(Heat)

A cricket ball of mass 0.15 kg is thrown vertically up by a bowling machine so that it rises to a maximum height of 20 m after leaving the machine. If the part pushing the ball applies a constant force F on the ball and moves horizontally a distance of 0.2 m while launching the ball, the value of F (in N) is (g = 10 ms?²)