1.

Part i. you considered the equilibrium: fe3+(aq) + scn-(aq) fe(scn)2+(aq), and compared the color of the solutions in four test

Alexus [3.1K]

Answer:

The equilibrium will be shifted to lift with the formation of a brown gelatinous precipitate of Fe(OH)₃.

Explanation:

Le Chatelier's principle states that "when any system at equilibrium for is subjected to change in concentration, temperature, volume, or pressure, then the system readjusts itself to counteract the effect of the applied change and a new equilibrium is established that is different from the old equilibrium".

The addition of NaOH will result in the formation of Fe(OH)₃ precipitate which has a brown gelatinous precipitate.

The formation of this precipitate cause removal and decrease of Fe³⁺ ions.

According to Le Chatelier's principle, the system will be shifted to lift to increase Fe³⁺ concentration and reduce the stress of Fe³⁺ removal and readjust the equilibrium again. So, the [Fe(SCN)²⁺] decreases.

Increasing [Fe³⁺] will produce a yellow color solution that contains a brown gelatinous precipitate of Fe(OH)₃.

3 0

2 years ago

If 45.0 mL of ethanol (density =0.789g/mol) initially at 6.0°C mix with 45.0 mL of water (density =1.0 g/mol) initially at 28.0°

Likurg_2 [28]

The final temperature of the mixture : 21.1° C

<h3>Further explanation </h3>

The law of conservation of energy can be applied to heat changes, i.e. the heat received / absorbed is the same as the heat released

Q in(gained) = Q out(lost)

Heat can be calculated using the formula:

Q = mc∆T

Q = heat, J

m = mass, g

c = specific heat, joules / g ° C

∆T = temperature difference, ° C / K

Q ethanol=Q water

mass ethanol=

$\tt mass=\rho\times V\\\\mass=0.789\times 45=35.505~g$

mass water =

$\tt mass=1~g/ml\times 45~ml=45~g$

then the heat transfer :

$\tt 35.505\times 2.42~J/g^oC\times (t-6)=45\times 4.18~J/g^oC\times (28-t)\\\\85.922t-515.533=5266.8-188.1t\\\\274.022t=5782.33\rightarrow t=21.1^oC$

5 0

2 years ago

Select the statements that correctly describe a buffer. a) An acid added to the buffer solution reacts with the weak base of the

Tom [10]

Answer:

(B.) The pH of a buffer solution is determined by the ratio of the concentration of conjugate base to the concentration of strong acid.
(C.) A buffer is generally made up of a weak acid and its conjugate base. 
(D.) The pH of a buffer solution does not change significantly when any amount of a strong acid is added.

Explanation:

A buffer is solution which resists change in pH upon addition of either acids or bases.

The pH of a buffer is calculated by the ratio of the concentration of base to concentration of acid. The weak acid and conjugate base have a Ka similar to the pH desired.

3 0

2 years ago

Describe how adding the prefix mega to a unit affects the quantity being described

neonofarm [45]

If the prefix mega is added to the unit of the quantity being described, the magnitude of quantity increases by 10^{6} times i.e. 1 million times.

For Example- 1 MW = 1000000 watts

5 0

2 years ago

How many moles are in 525 g of ammonia, NH3? 8940.75 M 0.03 M 30.83 M

victus00 [196]

Answer:

30.83 M

Explanation:

17.03052 re in one mole. So, if you multiply it by 30.83, you will get 535 g of ammonia.

In fact, the detailed answer is 30.827009392549122.

3 0

1 year ago

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