The main raw material for the manufacture of cement is: MCQ with Answer and Explanation

Explanation:
Na₂CO₃ is formed from NaOH (strong base) and H₂CO₃ (weak acid). Its aqueous solution is basic due to hydrolysis: CO₃²⁻ + H₂O ⇌ HCO₃⁻ + OH⁻. Strong acid + strong base salts are neutral (NaCl).

Explanation:
Charles' law: V ∝ T (Kelvin). So at constant P and n, V/T = constant. If temperature is in Celsius, proportionality is not direct because zero Celsius is not absolute zero. Absolute zero (0 K = -273.15°C) is the theoretical temperature at which volume becomes zero. A graph of V vs T (K) is a straight line through origin.

Explanation:
In an electrochemical cell, reduction (gain of electrons) always occurs at the cathode, regardless of whether the cell is electrolytic or galvanic. At the anode, oxidation (loss of electrons) occurs. Memory aid: 'RED CAT' (REDuction at CAThode), 'AN OX' (OXidation at ANode). In electrolysis, the cathode is connected to the negative terminal of the battery, attracting cations which get reduced.