Please help me find the answer , thank you.

What element is located in group 5, period 4?

djverab [1.8K]

Answer:

vanadium

Explanation:

3 0

3 years ago

A reaction A(aq)+B(aq)↽−−⇀C(aq) has a standard free‑energy change of −4.20 kJ/mol at 25 °C. What are the concentrations of A, B,

Dafna1 [17]

Answer : The concentration of $A,B\text{ and }C$ at equilibrium are 0.132 M, 0.232 M and 0.168 M respectively.

Explanation :

The given chemical reaction is,

$A(aq)+B(aq)\rightleftharpoons C(aq)$

First we have to calculate the equilibrium constant for the reaction.

The relation between the equilibrium constant and standard free‑energy is:

$\Delta G^o=-RT \ln k$

where,

$\Delta G^o$ = standard free‑energy change = -4.20 kJ/mole

R = universal gas constant = 8.314 J/mole.K

k = equilibrium constant = ?

T = temperature = $25^oC=273+25=298K$

Now put all the given values in the above relation, we get:

$-4.20kJ/mole=-(8.314J/mole.K)\times (298K) \ln k$

$k=5.45$

Now we have to calculate the concentrations of A, B, and C at equilibrium.

The given equilibrium reaction is,

$A(aq)+B(aq)\rightleftharpoons C(aq)$

Initially 0.30 0.40 0

At equilibrium (0.30-x) (0.40-x) x

The expression of equilibrium constant will be,

$k=\frac{[C]}{[A][B]}$

$5.45=\frac{x}{(0.30-x)\times (0.40-x)}$

By solving the term x, we get

$x=0.168\text{ and }0.716$

From the values of 'x' we conclude that, x = 0.716 can not more than initial concentration. So, the value of 'x' which is equal to 0.716 is not consider.

The value of x will be, 0.168 M

The concentration of $A$ at equilibrium = (0.30-x) = 0.30 - 0.168 = 0.132 M

The concentration of $B$ at equilibrium = (0.40-x) = 0.40 - 0.168 = 0.232 M

The concentration of $C$ at equilibrium = x = 0.168 M

3 0

4 years ago

Substance which allows energy to pass through it

Airida [17]

A substance which allows energy (heat or electricity) to pass through it is known as a conductor.

These substances usually have free electrons which allows the charges to flow easily in the substance, thus, transferring energy.

Other substances which do not have free electrons and do not allow energy to pass through them are known as insulators.

3 0

3 years ago

The Sunhawk, a car built by students at SUNY New Paltz, prompted Forbes Magazine to ask “Is The $250,000 Sunhawk theSolar Car of

olga2289 [7]

Answer:

The potential of energy availability at all locations where there is Sunlight

Explanation:

One advantage in owning a solar car is the potential of energy availability

The solar car source of energy is from the Sun which is readily available during the daytime where there is a clear sky. The energy from sunlight is converted to to electrical energy by the photovoltaic cells on solar panels installed on the roof area of solar powered cars

The energy from the Sunlight is a form of renewable energy and therefore allows for better stability as well as the possibility of reuse of the energy

There are no emissions from the use of solar cars including noise, making the solar car very environmentally friendly.

8 0

3 years ago

FIVE TRUE/FALSE please help

marin [14]

Answer:

9. false

10. true

11. false

12. true

13. true

Explanation:

9. a Newton is the SI unit of force.

11. it says energy can't be created or destroyed

8 0

3 years ago