TS EAMCET 2019 :: Chemistry :: General questions

• Chemistry - General questions

What is the bonding nature in LiCl bond?

Answer:

Explanation:

LiCl is ionic as well as covalent. LiCl is ionic because Li is metal and Cl is non-metal and has the electrostatic force of attraction between positive $(Li^{+})$ and negative ($Cl^{-}$) ion.

 LiCl is covalent because smaller size of $Li^{\oplus}$ easily polarise the larger size of $Cl^{-}$   ion. Thus, it is covalent as well as ionic 

The enthalpy change for freezing of 1 g of water at 1 bar and $0^{0}$ C is 334 J . Calculate the internal energy change in J when 1g of water is converted into ice?

Answer:

Explanation:

When 1 g water is converted  into ice then internal energy is equal to enthalpy  change for freezing at 1 bar and $0^{0}$ C

$1g H_{2}O(aq)\rightleftharpoons H_{2}O(ice)$

 Enthalpy change for freezing of 1g of water at 1 bar and $0^{0} $ C  temperature is 334 J .

Hence, internal energy equal to 334 J

A spherical ball of radius 7 cm contains 56 w% iron. Find out the number of moles of iron present approximately in the ball? 

(d=1.4 g cm^-3,  atomic mass =56 g mol^-1)

Answer:

Explanation:

 56 w% iron spherical ball has radius =7 cm

 Volume = $\frac{4}{3} \pi r^{3}= \frac{4}{3} \times 3.14 \times (7 \times 7 \times 7)$

  d=1.4 g/cm³

 n=$ \frac{ d \times 10 \times mass  \times volume}{atomic mass \times 1000}$

  n= $\frac{1.4 g/cm^{3} \times 10 \times 56 \times \frac{4}{3} \times 3.14 \times (7)^{3}}{56 \times 1000}$

   n=20.1 mol

Hence , option (b) is correct.

Which of the following compounds has the highest dipole moment (D)?

Answer:

Explanation:

(a)   Dipole  moment of HBr

(b)    Dipole moment of acetone

due to methyl group, (ERG)  lies in direction of oxygen  therefore, net dipole moment increases

    $\mu _{net}=2.69 D$

 (c)  Dipole moment of $H_{2}S$

$\mu _{net}=0.97 D$

 (d) Dipole moment of $COCl_{2}$

 due of Cl atom net dipole moment decreases.

$\mu _{net}=0.69 D$

 Hence, acetone has highest dipole moment 

 The maximum number of electrons that can have the set of quantum numbers, n=4, m_l=0  and m_s = 1/2  is

Answer:

Explanation:

Quantum number (n)=4, m_l=0, m_s = $\frac{1}{2}$ 

 Maximum number of electrons (n=4), =4

• Chemistry - General questions