Use the periodic to fill in the numbers in the electron configurations shown below

For the decomposition of hydrogen peroxide in dilute sodium hydroxide at 20 °C 2 H2O2(aq)2 H2O(l) + O2(g) the following data hav

saul85 [17]

Answer:

K= 0.06611

Explanation: The rate of reaction is defined as the change in concentration of any of reactant or products per unit time. From the given reaction, the rate of reaction may be equal to the rate of disappearance of reactant which is equal to the rate of appearance of products.

The average rate of disappearance of H2O2 over the time period from t=0 min at 8.92×10^-2 to t=9.63min at 4.72×10^-2 is given as -4.36×10^-3Mmin-1.

We can say:

•The initial concentration [H2O2]o is 8.92×10^-2M

•The concentration at time t. [H2O2]t is 4.72×10^-2

•The time (t) is 9.63 min

The expression of rate constant for a first order reaction is shown as

K=2.303/t log[H2O2]o/ [H2O2]t

Substitute the values of t, [H2O2]o and [H2O2]t in the equation of rate constant.

K=2.303/9.63 log [8.92×10^-2]/ [4.72×10^-2]

K= 0.2391 (log 8.92×10^-2 - log 4.72×10^-2)

K= 0.2391 [-1.0496-(-1.3261)]

K= 0.2391 (-1.0496+1.3261)

K= 0.2391 (0.2765)

K= 0.06611

Since the value of k is almost constant, the decomposition of H2O2 is a first order reaction.

4 0

3 years ago

PLEASE HELP!!

yanalaym [24]

Answer:

Remove a H2 molecule from the left side of the equation.

Explanation:

i took the quiz and got it right

8 0

2 years ago

Who discovered sodium?

Free_Kalibri [48]

Humphry Davy First discovered sodium

5 0

3 years ago

Read 2 more answers

A toxicologist studying mustard gas, S(CH2CH2Cl)2, a blistering agent, prepares a mixture of 0.675 M SCl2and 0.973 M C2H4 and al

Musya8 [376]

Answer:

The value of $K_p$ is 0.02495.

Explanation:

Initial concentration of $SCL_2$ gas = 0.675 M

Initial concentration of $C_2H_4$ gas = 0.973 M

Equilibrium concentration of mustard gas = 0.35 M

$SCl_2 (g) + 2 C_2H_4 (g)\rightleftharpoons S(CH_2CH_2Cl)_2(g)$

initially

0.675 M 0.973 M 0

At equilibrium ;

(0.675-0.35) M (0.973-2 × 0.35) M 0.35 M

The equilibrium constant is given as :

$K_c=\frac{[S(CH_2CH_2Cl)_2]}{[SCl_2][C_2H_4]^2}$

$=\frac{0.35 M}{(0.675-0.35) M\times ((0.973-2 × 0.35) M)^2}$

$K_c=14.45$

The relation between $K_p$ and $K_c$ are :

$K_p=K_c\times (RT)^{\Delta n}$

where,

$K_p$ = equilibrium constant at constant pressure = ?

$K_c$ = equilibrium concentration constant =14.45

R = gas constant = 0.0821 L⋅atm/(K⋅mol)

T = temperature = 20.0°C =20.0 +273.15 K=293.15 K

$\Delta n$ = change in the number of moles of gas = [(1) - (1 + 2)]=-2

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

$K_p=14.45\times (0.0821L.atm/K.mol\times 293.15 K)^{-2}$

$K_p=6.2\times 10^{4}$

$K_p=0.02495$

The value of $K_p$ is 0.02495.

7 0

3 years ago

What is the purpose of adding phenolphthalein to your Erlenmeyer flask prior to starting a titration?

koban [17]

Answer:

a. The phenolphthalein acts as a color changing indicator to signal the endpoint of the reaction.

Explanation:

Phenolphthalein is an organic substance with chemical formula $C_{20}H_{14}O_{4}$ .

It is a substance commonly used in acid-base titrations to indicate the end point in the titration because phenolphthalein is colorless in acidic solutions but turns a purplish-pink color in basic solutions.

In this way it helps visually to notice when the final point of the titration has been reached.

3 0

3 years ago