Which of the following is a precipitate in the reaction below?

Indicate whether each of the following compounds will gave an acidic, basic or neutral solution when dissolved in water. Clear A

allsm [11]

Answer: ammonium bromide : acidic : The pH will be less than 7.

potassium cyanide : basic :The pH will be more than 7.

calcium nitrate: neutral : The pH will be approximately equal to 7.

calcium hypochlorite : basic :The pH will be more than 7.

Explanation:

pH is defined as the negative logarithm of hydrogen ion concentration. The scale ranges from 0 to 14.

When a solution is acidic, it will show a pH in the range of 0 - 6.9. When a solution is basic, it will show a pH in the range of 7.1 - 14. When a solution is neutral, it will show a pH of 7.

ammonium bromide : $NH_4Br$ : acidic as it is formed from the combination of strong acid HBr and weak base $NH_4OH$

potassium cyanide : $KCN$ : basic, as it is formed from the combination of weak acid HCN and strong base KOH

calcium nitrate: $Ca(NO_3)_2$ : neutral, as it is formed from the combination of strong acid and strong base.

calcium hypochlorite : $Ca(ClO)_2$ : basic, as it is formed from the combination of weak acid $HOCl$ and strong base $Ca(OH)_2$

3 0

3 years ago

A hot air balloon, when fully inflated, contains 2,800,000 Liter of air. If each mole of air occupies 22.4 L of at a temperature

emmainna [20.7K]

Answer:

1.44 atm

Explanation:

Step 1:

We'll begin by calculating the number of mole in 2,800,000 Liter of air.

I mole of air occupy 22.4L.

Therefore, Xmol of air will occupy 2800000L i.e

Xmol of air = 2800000/22.4

Xmol of air = 125000 moles

Step 2:

Determination of the pressure when the balloon is fully inflated .

This can be obtained as follow:

Number of mole (n) of air = 125000 moles

Volume (V) = 2800000 L

Temperature (T) = 120°C = 120°C + 273 = 393K

Gas constant (R) = 0.082atm.L/Kmol

Pressure (P) =.?

PV = nRT

Divide both side V

P= nRT/V

P= (125000x0.082x393) / 2800000

P = 1.44 atm

Therefore, the pressure of the air when the balloon is fully inflated is 1.44 atm

3 0

3 years ago

Please help last assignment of the day

Andrej [43]

In this qn, you use the mole formula,

amount (mol) = mass (g) ÷ molar mass

(molar mass is the mass number of an element, which u can find by referring to the periodic table)

so by subbing in the values given to you, you can find the answer

5. amount of Cu = 55.9 ÷ 63.5 = 0.880mol (3sf)

6. amount of N2 = 340 ÷ 2(14.0) = 12.1mol (3sf)

(note: you multiply the molar mass of N by 2 as there are 2 N atoms)

for qn 7 and 8, youre finding the mass and not the amount. By bringing the molar mass over to the other side of the formula, you get

mass = amount (mol) × molar mass

thus,

7. mass of Fe = 0.063 × 55.8 = 3.52g (3sf)

8. mass of H2 = 94.7 × 2(1.0) = 47.4g (3sf)

extra things to take note of:

- likewise, you can also find the molar mass of an element by using

molar mass = mass(g) ÷ amount(mol)

^^ this is commonly only needed when you need to find the molar mass of an isotope. the question will give you the amount and mass of the element, and you just need to factor them in to find your answer.

- typically, you use 3 sf in your final answer and 5sf in your working. remember to write (3sf) at the end of your number statement when necessary.

- when you get an answer of (eg.) 0.6mol, you still need to write it in 3sf, so your answer would be 0.600mol

3 0

3 years ago

A 0.539 g sample of a metal, M, reacts completely with sulfuric acid according to the reaction M(s)+H2SO4(aq)⟶MSO4(aq)+H2(g) A v

Charra [1.4K]

Answer:

The molar mass of the metal is 54.9 g/mol.

Explanation:

When we work with gases collected over water, the total pressure (atmospheric pressure) is equal to the sum of the vapor pressure of water and the pressure of the gas.

Patm = Pwater + PH₂

PH₂ = Patm - Pwater = 1.0079 bar - 0.03167 bar = 0.9762 bar

The pressure of H₂ is:

$0.9762bar.\frac{1atm}{1.013bar} =0.9637atm$

The absolute temperature is:

K = °C + 273 = 25°C + 273 = 298 K

We can calculate the moles of H₂ using the ideal gas equation.

$P.V=n.R.T\\n=\frac{P.V}{R.T} =\frac{0.9637atm \times 0.249L }{(0.08206atm.L/mol.K)\times298K} =9.81 \times 10^{-3} mol$

Let's consider the following balanced equation.

M(s) + H₂SO₄(aq) ⟶ MSO₄(aq) + H₂(g)

The molar ratio of M:H₂ is 1:1. So, 9.81 × 10⁻³ moles of M reacted. The molar mass of the metal is:

$\frac{0.539g}{9.81 \times 10^{-3} mol} =54.9g/mol$

4 0

4 years ago

What can you determine about the feasibility of a reaction if the enthalpy is positive and

kvasek [131]

If the enthalpy is positive and the entropy is positive, the Gibbs energy will always be positive, and the reaction will never be feasible.

<h3>What is the Gibbs Free Energy?</h3>

The Gibb Free Energy is used to obtain the feasibility of a reaction. If the Gibbs free energy is positive the reaction is not spontaneous. If the value is negative, the reaction is spontaneous while a zero values indicates equilibrium.

From the equation;

ΔG = ΔH - TΔS, it follows that if the enthalpy is positive and the entropy is positive, the Gibbs energy will always be positive, and the reaction will never be feasible.

Learn more about Gibbs Free energy:brainly.com/question/20358734

#SPJ1

7 0

2 years ago