Which components of a galaxy move in circular patterns or revolve around a star?

Calculate the Ka for the following acid. Determine if it is a strong or weak acid. HClO2(aq) dissolves in aqueous solution to fo

Talja [164]

Answer:

The value of Ka $= 1.1*10^{-2}$

It is a weak acid

Explanation:

From the question we are told that

The concentration of $[HClO_2]=0.24M$

The concentration of $[H^+]=0.051M$

The concentration of $[ClO_2^-]=0.051M$

Generally the equation for the ionic dissociation of $HClO_2$ is

$HClO_2_(aq) -------> H^{+}_{(aq)} + ClO_2^{-}_{(aq)}$

The equilibrium constant is mathematically represented as

$Ka = \frac{concentration \ of \ product }{concentration \ of \ reactant }$

$= \frac{[H^+][ClO_2^-]}{[HClO_2]}$

Substituting values since all value of concentration are at equilibrium

$Ka = \frac{0.051 * 0.051}{0.24}$

$= 1.1*10^{-2}$

Since the value of is less than 1 it show that in water it dose not completely

disassociated so it an acid that is weak

3 0

3 years ago

A 10-gram sample of zinc loses 560 J of heat and has a final temperature of 100

grandymaker [24]

<h3>Answer:</h3>

Initial temperature is 243.59°C

<h3>Explanation:</h3>

The quantity of heat is calculated by multiplying the mass of a substance by its specific heat capacity and change in temperature.

That is; Q = m×c×ΔT

In this case;

Quantity of heat = 560 J

Mass of the Sample of Zinc = 10 g

Final temperature = 100°C

We are required to determine the initial temperature;

This can be done by replacing the known variables in the formula of finding quantity of heat,

Specific heat capacity, c, of Zinc = 0.39 J/g.°C

Therefore,

560 J = 10 g × 0.39 J/g°C × ΔT

ΔT = 560 J ÷ (3.9 J/°C)

= 143.59°C

But, since the sample of Zinc lost heat then the temperature change will have a negative value.

ΔT = -143.59°C

Then,

ΔT = T(final) - T(initial)

Therefore,

T(initial) = T(final) - ΔT

= 100°C - (-143.59°C)

= 243.59°C

Hence, the initial temperature of zinc sample is 243.59°C

5 0

3 years ago

Find the standard enthalpy of formation of ethylene, C2H4(g), given the following data: C2H4(g) + 3 O2(g) --> 2CO2(g) + 2 H2O

Brums [2.3K]

Answer : The standard enthalpy of formation of ethylene is, 52.4 kJ

Explanation :

According to Hess’s law of constant heat summation, the heat absorbed or evolved in a given chemical equation is the same whether the process occurs in one step or several steps.

According to this law, the chemical equation can be treated as ordinary algebraic expression and can be added or subtracted to yield the required equation. That means the enthalpy change of the overall reaction is the sum of the enthalpy changes of the intermediate reactions.

The formation reaction of $C_2H_4$ will be,

$2C(s)+2H_2(g)\rightarrow C_2H_4(g)$ $\Delta H_{formation}=?$

The intermediate balanced chemical reaction will be,

(1) $C_2H_4(g)+3O_2(g)\rightarrow 2CO_2(g)+2H_2O(l)$ $\Delta H_1=-1411kJ$

(2) $C(s)+O_2(g)\rightarrow CO_2(g)$ $\Delta H_2=-393.5kJ$

(3) $H_2(g)+\frac{1}{2}O_2(g)\rightarrow H_2O(l)$ $\Delta H_3=-285.8kJ$

Now we will reverse the reaction 1, multiply reaction 2 and 3 by 2 then adding all the equation, we get :

(1) $2CO_2(g)+2H_2O(l)\rightarrow C_2H_4(g)+3O_2(g)$ $\Delta H_1=+1411kJ$

(2) $2C(s)+2O_2(g)\rightarrow 2CO_2(g)$ $\Delta H_2=2\times (-393.5kJ)=-787kJ$

(3) $2H_2(g)+2O_2(g)\rightarrow 2H_2O(l)$ $\Delta H_3=2\times (-285.8kJ)=-571.6kJ$

The expression for enthalpy of formation of $C_2H_4$ will be,

$\Delta H_{formation}=\Delta H_1+\Delta H_2+\Delta H_3$

$\Delta H=(+1411kJ)+(-787kJ)+(-571.6kJ)$

$\Delta H=52.4kJ$

Therefore, the standard enthalpy of formation of ethylene is, 52.4 kJ

7 0

3 years ago

Applying a force can make an electron shift from one atom to another causing what?

Alexus [3.1K]

Electrons in atoms can act as our charge carrier, because every electron carries a negative charge. If we can free an electron from an atom and force it to move, we can create electricity.

8 0

3 years ago

Which is the best explanation of why heat is released when

vazorg [7]

The answers is A. Reales energy stored in chemical bonds

6 0

3 years ago