If $P(1, 2)$,$Q(4, 6)$,$R(5, 7)$,and $S(a, b)$ are the vertices of a parallelogram $PQRS$,then:

$\int(x+1)^2 e^x d x$ is equal to

$A$ $500\,\mu F$ capacitor is charged at a steady rate of $100\,\mu C/s$. The potential difference across the capacitor will be $10\,V$ after an interval of $......\,s$.

If $4x^2 - 5xy + y^2 = 0$ represents a pair of lines with slopes $m_1$ and $m_2$,then the value of $|m_1 - m_2|$ equals

In which of the following molecules/ions are all the bonds not equal?

Solution $X$ contains $Na_2CO_3$ and $NaHCO_3$. $20 \ mL$ of $X$ when titrated using methyl orange indicator consumed $60 \ mL$ of $0.1 \ M$ $HCl$ solution. In another experiment,$20 \ mL$ of $X$ solution when titrated using phenolphthalein consumed $20 \ mL$ of $0.1 \ M$ $HCl$ solution. The concentrations (in $mol \ L^{-1}$) of $Na_2CO_3$ and $NaHCO_3$ in $X$ are respectively: