An atom of boron has an atomic number of 5 and an atomic mass of 11. The atom contains (2 points)

Deuterium is the isotope of hydrogen of mass number 2, with a proton and a neutron in its nucleus. The chemistry of deuterium is

s344n2d4d5 [400]

Answer:

True

Explanation:

We know that the zero-point-energy of a C-D system is quite lower than the zero point energy of the C-H bond so the C-D bond is stronger.

Kinetic isotope effect refers to the change in the rate of reaction owing to a change of one of the atoms of the reactants by replacing it with one of its isotopes.

Since we know that the C-D bond is stronger than the C-H bond, when we replace hydrogen with deuterium in a reaction's rate determining step we experience a little lag in the rate of reaction. This is referred to as the kinetic isotope effect in physical organic chemistry.

6 0

3 years ago

Given that Δ H ∘ f [ Br ( g ) ] = 111.9 kJ ⋅ mol − 1 Δ H ∘ f [ C ( g ) ] = 716.7 kJ ⋅ mol − 1 Δ H ∘ f [ CBr 4 ( g ) ] = 29.4 kJ

JulsSmile [24]

Answer:

283.725 kJ ⋅ mol − 1

Explanation:

C(s) + 2Br2(g) ⇒ CBr4(g) , Δ H ∘ = 29.4 kJ ⋅ mol − 1

$\frac{1}{2}$ Br2(g) ⇒ Br(g) , Δ H ∘ = 111.9 kJ ⋅ mol − 1

C(s) ⇒ C(g) , Δ H ∘ = 716.7 kJ ⋅ mol − 1

4*eqn(2) + eqn(3) ⇒ 2Br2(g) + C(s) ⇒ 4 Br(g) + C(g) , Δ H ∘ = 1164.3 kJ ⋅ mol − 1

eqn(1) - eqn(4) ⇒ 4 Br(g) + C(g) ⇒ CBr4(g) , Δ H ∘ = -1134.9 kJ ⋅ mol − 1

so,

average bond enthalpy is $\frac{1134.9}{4}$ = 283.725 kJ ⋅ mol − 1

4 0

3 years ago

Coal can be used to generate hydrogen gas (a potential fuel) by thefollowing endothermic reaction.C(s) + H2O (g) <==> CO(g

SpyIntel [72]

Explanation:

Any change in the equilibrium is studied on the basis of Le-Chatelier's principle.

This principle states that if there is any change in the variables of the reaction, the equilibrium will shift in the direction to minimize the effect.

For the given equation:

$C(s) + H_2O (g)\leftrightharpoons CO(g) + H_2(g)$

Given that reaction is an endothermic reaction.

For the given options:

a)Adding more C

If the concentration of C that is the reactant is increased, so according to the Le-Chatlier's principle, the equilibrium will shift in the direction where decrease of concentration of C takes place. Therefore, the equilibrium will shift in the right direction to wards the formation of hydrogen gas.

b) Adding more $H_2O$

If the concentration of water that is the reactant is increased, so according to the Le-Chatlier's principle, the equilibrium will shift in the direction where decrease of concentration of water takes place. Therefore, the equilibrium will shift in the right direction towards the formation of hydrogen gas.

c) Raising the temperature of the reaction mixture

If the temperature is increased,heat of the equilibrium mixture will also increase so according to the Le-Chatlier's principle , the equilibrium will shift in the direction where decrease in heat that is decrease in temperature occurs.

As, this is an endothermic reaction, forward reaction will decrease the temperature. Hence, the equilibrium will shift in the right direction that is towards the formation of hydrogen gas.

d) Increasing the volume of reaction mixture

If the volume of the container is increased, the pressure will decrease according to Boyle's Law. Now, according to the Le-Chatlier's principle, the equilibrium will shift in the direction where increase in pressure is taking place. As the number of moles of gas molecules is greater at the product side. So, the equilibrium will shift in the right direction that is towards the formation of hydrogen gas.

e) Adding a catalyst to reaction mixture

Role of catalyst is to attain the equilibrium quickly without disturbing the state of equilibrium. Hence, addition of catalyst will not change the equilibrium of the reaction.

f) Adding an inert gas to reaction mixture

Adding inert gas to the mixture at constant volume will not effect the equilibrium. Hence, addition of an inert gas will not change the equilibrium of the reaction.

6 0

3 years ago

Explain the units and how to solve the following metric conversion then solve the metric conversion by filling in the blank 12KM

LiRa [457]

Answer:- 12 km = 12000 m

Solution:- It's a metric unit conversion where we are asked to convert 12 km to m where km stands for kilometer and m stands for meter.

In metric conversions, kilo means 1000.

So, 1 km = 1000 m

It means, we multiply the given km by 1000 to get the answer in m as:

$12km(\frac{1000m}{1km})$