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3 years ago

Why should distilled water be used when conducting chemical tests?

Chemistry

1 answer:

pishuonlain [190]3 years ago

8 0

Explanation:

Water is used in many tests as solvent for dissolving solutes.

No ions, compounds or salts are present in distilled water. Therefore, test result will not be affected by distilled water.

If plain water is used instead of distilled water, the ions or other salts present in plain water, may undergo chemical reaction with the reagent and may affect the test result.

Consider an example,

Concentration of $Fe^{2+}$ is determined by potassium permanganate using titration method

solution of both $Fe^{2+}$ and potassium permanganate are made in water.

Potassium permanganate is titrant and $Fe^{2+}$ is used as titrand.

Concentration of $Fe^{2+}$ is determined by end point. if the water used for making solution is not distilled, it may affect end point, which results in incorrect determination of concentration of $Fe^{2+}$ .

Therefore, distilled should be used for chemical tests.

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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

Write the action of monohydroxy benzene with aqueous bromine

Romashka-Z-Leto [24]

The reaction yields the product compound 2,4,5-tribromophenol.

<h3>Bromination of monohydroxy benzene</h3>

Bromination is an organic reaction in which aqueous bromine is made to react with another compound so as to introduce bromine into the molecule.

When we carry out the bromination of monohydroxy benzene, we obtain the compound 2,4,5-tribromophenol.

Learn more about benzene: brainly.com/question/14525517

5 0

3 years ago

A slice of Swiss cheese contains 47 mg of sodium. (a) What is this mass in grams? .047 (b) What is this mass in ounces? (16 oz =

MAVERICK [17]

Answer:

(a) 0.047 g (b) 0.0016 oz (c) 0.0001 lb

Explanation:

The given mass of the sodium in the slice = 47 mg

(a) Mass has to be calculated in grams

The conversion of mg to g is shown below as: