Answer:
Sprinkling of powder on the carom board <u>reduces</u> friction.
Lewis had proposed that the valence electrons of any substance were arranged around its atoms in a cubic configuration. Later on, this was modified when it was learned that the electrons actually orbit the nucleus, similar to the planets orbiting the sun. Moreover, it is now deduced that the electrons are found in regions, known as electron clouds, and their specific, discrete location at a given point in time can not be determined.
For this problem we can use 2 equations.
(1) - E = mC²
E = Energy of photon (J)
m = Mass of photon (kg) (1.67x10⁻²⁷ kg)
C = speed of light (3 x 10⁸ m/s)
(2) - E = hf
E = Energy of photon (J)
h = plank's constant (6.63 × 10⁻³⁴<span>J s)
f = frequency of the photon (Hz)
(1) = (2)
hence, </span>mC² = fh
by rearranging,
f = mC² / h
f = 1.67x10⁻²⁷ kg * (3 x 10⁸ m/s)² / (6.63 × 10⁻³⁴J s)
f = 2.27 x 10²³ Hz
Answer:
NO.3) Mass of Al2O3 formed = 229.5g
Answer:
Heat released =811.68kcal
Explanation:
2 CO(g) + O2(g) → 2 CO2(g) ΔH=-135.28kcal
for this type of question 1st balance the chemical reaction and use unitry method.
From the above balanced equaion it is clearly that,
2 mole of CO reacts with 1 mole of O2 and we have sufficient amount of oxygen means excess amount.
and also for complete consumption of 2 mole of CO, ΔH=-135.28 kcal
for complete consumption of 12 moles of CO2 ΔH=
Heat released =811.68kcal
