The chemical formula of hydrogen peroxide is H2O2. We know that hydrogen always has +1 oxidation state until it forms metal hydrides. So in H2O2, the oxidation state ofhydrogen is +1.

Now, let oxidation state of oxygen be x. So,

2 * (+1) + 2*x = 0

2 + 2x = 0

2x = -2

x = -2 / 2

x = -1

Hence, the oxidation number of oxygen in peroxides is -1

6 0

2 years ago

Calculate the standard entropy of vaporization of ethanol, C2H5OH, at 285.0 K, given that the molar heat capacity at constant pr

MArishka [77]

Answer: The standard entropy of vaporization of ethanol is 0.275 J/K

Explanation:

$C_2H_5OH(l)\rightleftharpoons C_2H_5OH(g)$

Using Gibbs Helmholtz equation:

$\Delta G=\Delta H-T\Delta S$

For a phase change, the reaction remains in equilibrium, thus $\Delta G=0$

$\Delta H=T\Delta S$

Given: Temperature = 285.0 K

$\Delta H=78.3J/mol$

Putting the values in the equation:

$78.3J=285.0K\times \Delta S$

$\Delta S=0.275J/K$

Thus the standard entropy of vaporization of ethanol is 0.275 J/K

4 0

3 years ago

A brick has a mass of 4.0 kg and the Earth has a mass of 6.0 × 1027 g. Use this information to answer the questions below. Be su

Vedmedyk [2.9K]

Answer:

a) $2.4\times 10^{24} kg$ is the mass of 1 mole of bricks.

b) $2.5\times 10^3$ moles of bricks have a mass equal to the mass of the Earth.

Explanation:

a) Mass of brick = 4.0 kg

1 mole = $N_A=6.022\times 10^{23}$ particles/ atoms/molecules

Mass of $N_A$ bricks :

$=6.022\times 10^{23}\times 4.0 kg=2.4088\times 10^{24} kg\approx 2.4\times 10^{24} kg$

$2.4\times 10^{24} kg$ is the mass of 1 mole of bricks.

Mass of the Earth = M = $6.0\times 10^{27} kg$

Mass of 1 mole of brick = m= $2.4\times 10^{24} kg$

Let the moles of brick with equal mass of the Earth be x.

$m\times x=M$

$x=\frac{M}{m}=\frac{6.0\times 10^{27}kg}{2.4\times 10^{24} kg}=2.5\times 10^3$

$2.5\times 10^3$ moles of bricks have a mass equal to the mass of the Earth.

7 0

3 years ago