Tag: chemistry

In the balanced equation for combustion of 1 mole of butane, $C _4H _{10}(g)$, the coefficient of oxygen is:

Standard enthalpy of formation $(\Delta H _f)$ of which of the following is zero at $25^0C$ ?

The enthalpy of hydrogenation for $1-pentene$ is $+126\ kJ/mol$. The enthalpy of hydrogenation for $1, 3-pentadiene$ is $+230\ kJ/mol$. Hence estimate the resonance magnitude of (delocalization) energy of $1, 3-pentadiene$.

The least stable in amongst the following is:

The heats of neutralization of $CH _3COOH.HCOOH, HCN$ and $HClO$ are 13.2, 13.4,2.9 and 3.6 kcal/eq respectively. Then, the degree of hydrolysis for the respective ions will be in the order :

The heat change for the reaction: $C(s) + S(s)\rightarrow CS _2(l)$, known as:

Enthalpy of a solution of $ CsBr(s)$ is $10\ kJ/mol$.If the enthalpies of hydration of $Cs^+(g)$ and $Br(g)$ are 475 and 655 kJ.mol, what should be the lattice energy of $CsBr(s)$ in $kJ/mol$:

Which statement about bonding is not correct?

Covalent bonds are formed when electrons are $1$ .
Most covalent compounds have $2$ electrical conductivity.
Which words correctly complete gaps $1$ and $2$?