The correct answer is (A): CaCO3 and Mg(OH)2
\(Ca(HCO_3)_2\)\(\stackrel{Δ}{→}\) \(CaCO_3\) \(↓\) +\(H_2O\) + \(CO_2\) \(↑\)
\(Mg(HCO_3)_2\)\(\stackrel{Δ }{→}\) \(Mg(OH)_2\)+ \(2CO_2\)\(↑\)
| List-I (Species) | List-II (Maximum allowed concentration in ppm in drinking water) | ||
| A | F- | I | < 50 ppm |
| B | \(SO^{2-}_4\) | II | < 5 ppm |
| C | \(NO^-_3\) | III | < 2 ppm |
| D | Zn | IV | < 500 ppm |
Choose the correct answer from the options given below :
Solute A associates in water. When 0.7 g of solute A is dissolved in 42.0 gof water, it depresses the freezing point by 0.2°C. The percentage association of solute A in water is :
[Given : Molar mass of A = 93 g mol–1. Molal depression constant of water is 1.86 K kg mol–1.]
Inductance of a coil with \(10^4\) turns is \(10\,\text{mH}\) and it is connected to a DC source of \(10\,\text{V}\) with internal resistance \(10\,\Omega\). The energy density in the inductor when the current reaches \( \left(\frac{1}{e}\right) \) of its maximum value is \[ \alpha \pi \times \frac{1}{e^2}\ \text{J m}^{-3}. \] The value of \( \alpha \) is _________.
\[ (\mu_0 = 4\pi \times 10^{-7}\ \text{TmA}^{-1}) \]
A small block of mass \(m\) slides down from the top of a frictionless inclined surface, while the inclined plane is moving towards left with constant acceleration \(a_0\). The angle between the inclined plane and ground is \(\theta\) and its base length is \(L\). Assuming that initially the small block is at the top of the inclined plane, the time it takes to reach the lowest point of the inclined plane is _______. 
Heavy water (2H2O, D2O - deuterium oxide) is a form of water that consists only of deuterium rather than the common hydrogen-1 isotope that composes most of the hydrogen in normal water. The presence of the heavier hydrogen isotope gives the water distinct nuclear properties, and the increase of mass gives it slightly distinct physical and chemical properties when compared to normal water.