📚NCERT Questions
1,675 solved questions with detailed explanations
A 25-watt bulb emits monochromatic yellow light of wavelength 0.57 μm. Calculate the rate of emission of quanta per second. (h = 6.626 x 10⁻³⁴ J s, c = 3.00 x 10⁸ m s⁻¹)
In a balanced thermochemical equation, what do the coefficients refer to?
Calculate the enthalpy change on freezing of 1.0 mol of water at 10.0°C to ice at -10.0°C. Given: Δ_fus H = 6.03 kJ mol⁻¹ at 0°C, C_p[H₂O(l)] = 75.3 J mol⁻¹ K⁻¹, C_p[H₂O(s)] = 36.8 J mol⁻¹ K⁻¹.
Metallic oxides are generally considered:
What is lattice enthalpy?
According to Saytzeff's rule, in dehydrohalogenation reactions, the preferred product is the alkene that:
Which polyhalogen compound was once widely used as a general anaesthetic but was replaced by less toxic alternatives?
Why is agitation necessary to get clean clothes when using soap?
How many shared pairs of electrons constitute a double bond, as seen in an oxygen molecule (O2)?
According to IUPAC conventions in chemical thermodynamics, when work is done ON the system, what is the sign of w_ad and its effect on internal energy?