At 40°C, how much KNO3 is soluble?

Gallium is produced by the electrolysis of a solution obtained by dissolving gallium oxide in concentrated NaOH(aq). Calculate t

Alina [70]

Answer: The mass of gallium produced by the electrolysis is 0.0354 grams.

Explanation:

The equation for the deposition of Ga(s) from Ga(III) solution follows:

$Ga^{3+}(aq.)+3e^-\rightarrow Ga(s)$

To calculate the total charge, we use the equation:

$C=I\times t$

where,

C = charge

I = current = 0.490 A

t = time required (in seconds) = $50\times 60=300s$ (Conversion factor: 1 min = 60 s)

Putting values in above equation, we get:

$C=0.490\times 300=147C$

To calculate the moles of electrons, we use the equation:

$\text{Moles of electrons}=\frac{C}{F}$

where,

C = charge = 147 C

F = Faradays constant = 96500

$\text{Moles of electrons}=\frac{147}{96500}=1.52\times 10^{-3}mol$

Now, to calculate the moles of gallium, we use the equation:

$\text{Moles of Gallium}=\frac{\text{Moles of electrons}}{n}$

where,

n = number of electrons transferred = 3

Putting values in above equation, we get:

$\text{Moles of Gallium}=\frac{1.52\times 10^{-3}}{3}=5.077\times 10^{-4}mol$

To calculate the mass of gallium, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

Moles of Gallium = $5.077\times 10^{-4}mol$

Molar mass of Gallium = 69.72 g/mol

Putting values in above equation, we get:

$5.077\times 10^{-4}mol=\frac{\text{Mass of Gallium}}{69.72g/mol}\\\\\text{Mass of Gallium}=0.0354g$

Hence, the mass of gallium produced by the electrolysis is 0.0354 grams.

8 0

3 years ago

Which answer best explains why Mendeleev's periodic table became the first widely accepted organized scheme for the elements?

mrs_skeptik [129]

Well Mendeleev predicted the existence and properties of elements that werent discovered at the time

3 0

3 years ago

1. Explain how energy that is transferred is different from energy that is transformed.

igor_vitrenko [27]

Answer:

transferred means move from one place to another transformed means make a thorough or dramatic change in the form, appearance, or character of.

Explanation:

6 0

3 years ago

Use the diagram to answer each question.

Naya [18.7K]

Answer:

84g Thus, 84g of KNO3 must be dissolve in 100 grams of water to form a saturated solution at 50 oC.

and 136 of KNO3 must be dissolve in 100 grams of water to form a saturated solution at 70 oC.

Explanation:

4 0

3 years ago

What change in volume results if 75.0 mL of gas is cooled from 100.0 °C to 0.00 °C

Ksenya-84 [330]

Answer:

Final volume v2 = 0 ml

Explanation:

Given:

Initial temperature = 100°C

Initial volume = 75 ml

Final temperature = 0°C

Find:

Final volume

Computation:

Using Charles law formula;

⇒ V1 / T1 = V2 / T2

Where

⇒ Initial temperature = T1

⇒ Initial volume = V1

⇒ Final temperature = T2

⇒ Final volume = V2

So,

⇒ 75 / 100 = V2 / 0

Final volume v2 = 0 ml

5 0

3 years ago