Can anyone solve all of these?

4. 50.02 g of (NH₄)₂S

5. 7.12 g of Ga₂O₃

6. 55.07 g of NiCl₂

7. 30.6 %

Thanksful, you have the answers!

Explanation:

4. Reaction: 2NH₃ + H₂S → (NH₄)₂S

We determine the limiting reagent. For that propose we convert the mass of reactants to moles:

25 g / 17 g/mol = 1.47 moles of ammonia

96 g / 34.06 g/mol = 2.82 moles of sulfur

1 mol of sulfur hydrogen reacts with 2 moles of ammonia

2.82 moles of H₂S will react with (2.82 . 2) /1 = 5.64 moles of ammonia.

Clearly, the NH₃ is the limiting reactant.

2 moles of ammonia produce 1 mol of ammonium sulfur

Then, 1.74 moles of ammonia will produce (1.47 . 1) / 2 = 0.735 moles of sulfur. We convert the moles to mass:

0.735 mol . 68.06 g / 1mol = 50.02 g

5. Word equation:

Gallium reacts with oxygen in order to produce gallium oxide.

Formula equation: 4Ga + 3O₂ →  2Ga₂O₃

We convert the mass of reactants to moles:

5.3 g / 69.72 g/mol = 0.0760 moles of Ga

5.3 g / 32 g/mol = 0.166 moles of O₂

3 moles of oxygen react with 4 moles of Ga

Therefore, 0.166 moles of O₂ will react with (0.166 . 4) / 3 = 0.221 moles of Ga. As we do not have the amount required, Ga is the limiting reactant.

4 moles of Ga, can produce 2 moles of gallium oxide

0.0760 moles of Ga will produce (0.0760 . 2) /4 = 0.0380 moles of Ga₂O₃

We convert the moles to mass: 0.0380 mol . 187.44 g / 1 mol = 7.12 g of Ga₂O₃

6. Reaction is: 3CaCl₂ + Ni₃(AsO₄)₂ → 3 NiCl₂ + Ca₃(AsO₄)₂

47.2 g / 110.98 g/mol = 0.425 moles of chloride

135.2 g / 453.91 g /mol = 0.298 moles of  Ni₃(AsO₄)₂

1 mol of  Ni₃(AsO₄)₂ reacts with 3 moles of calcium chloride

Then, 0.298 moles will react with (0.298 . 3)/ 1 = 1.27 moles of CaCl₂

Clearly, the CaCl₂ is the limiting reactant.

Ratio is 3:3, 3 moles of CaCl₂ can produce 3 moles of NiCl₂. Therefore 0.425 moles will produce the same amount of NiCl₂.

We convert the moles to mass: 0.425 mol. 129.59 g /1mol = 55.07 g of NiCl₂

7. Let's determine the reaction:

C₂H₄ + 3O₂ → 2CO₂ + 2H₂O

As the oxygen is in excess, the limiting reagent is the ethene. We convert the mass to moles → 170.9 g / 28 g/mol = 6.10 moles

So, in the theoretical yield 1 mol of ethene can produce 2 moles of CO₂

Therefore 6.10 moles will produce (6.10 . 2) /1 = 12.20 moles of CO₂

The mass produced is 536.8 g (12.20 mol . 44 g /1mol)

In order to determine the percent yield we have to apply this formula

(Produced yield/Theoretical yield) . 100

We replace data: (164.1 g / 536.8 g) .100 = 30.6 %

IKI solution looks for starches, while Benedict's looks for sugars. IKI is iodine potassium iodide, which turns a dark blue when in the presence of amylase. Benedict's reagent is often used to look for reducing sugars, such as glucose, and turns colors ranging from a light green to a dark-red or brown with a cuprous precipitate in the presence of higher quantities of sugars in the tested solution.