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2 years ago

True/False 1. A compound makes up an atom Explain

Chemistry

1 answer:

lana [24]2 years ago

5 0

Answer: True

Explanation: The answer is true because A compound is a molecule made of atoms from different elements. All compounds are molecules, but not all molecules are compounds. … There are two main types of chemical bonds that hold atoms together: covalent and ionic/electrovalent bonds. Atoms that share electrons in a chemical bond have covalent bonds.

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What is the total charge of all the protons in 2.2 mol of he gas?

Tasya [4]

To determine the total charge of the protons in the gas, we need to know the number of protons that are present. We use Avogadro's number to know such value. We do as follows:

2.2 mol ( 6.022x10^23 protons / 1 mol ) = 1.325x10^24 protons

Total charge = 1.6021766208×10^−19 C (1.325x10^24) = 212262.77 C

3 0

3 years ago

When aqueous solutions of potassium fluoride and hydrochloric acid are mixed, an aqueous solution of potassium chloride and hydr

Neko [114]

Answer:

F⁻(aq) + H⁺(aq) ⇄ HF(aq)

Explanation:

When aqueous solutions of potassium fluoride and hydrochloric acid are mixed, an aqueous solution of potassium chloride and hydrofluoric acid results. The corresponding molecular equation is:

KF(aq) + HCl(aq) ⇄ KCl(aq) + HF(aq)

The full ionic equation includes all the ions and the molecular species. HF is a weak acid so it exists mainly in the molecular form.

K⁺(aq) + F⁻(aq) + H⁺(aq) + Cl⁻(aq) ⇄ K⁺(aq) + Cl⁻(aq) + HF(aq)

The net ionic equation includes only the ions that participate in the reaction (not spectator ions) and the molecular species.

F⁻(aq) + H⁺(aq) ⇄ HF(aq)

5 0

4 years ago

Chemistry! Help! Please!

Ratling [72]

Question 1

The correct answer is a.

Explanation

The relationship between $pH$ and $pOH$ is given by

$pH + pOH = 14$ , We can use $pH=-log[H^+]$ and $pOH= -log[OH^-]$ . In a we are given the concentration of [OH] and so we use that to find the pOH, then from pOH we can find the pH.

$pOH= -log [2.4 \times 10^-^2] = 1.62\\\\pH = 14 - 1.62= 12.38$

$b.pH=-log(1.53 \times 10^-^2) = 1.82$

c. HCl is a strong acid so it dissociates to 0.0001 $H^+$ and 0.0001 $Cl^-$ , hence

$pH= -log[0.0001] = 4$

$d.pOH= -log [4.4 \times 10^-9] = 8.36\\\\pH= 14- 8.36 = 5.64$

$a.[OH^-] = 2.4 \times 10^-^2$ has a pH 12.36 which is greater than 7

Question 2

The correct answer is d $O_2(g)$ .

Explanation

This is because solids and liquids do not appear in the equilibrium constant expression. Since $K= \frac{[products]}{[reactants]}$ .

For the equation

$2PbS_(_s_) + 3O_2_(_g_) + C_(_s_) \implies 2Pb _(_s_) + CO_2_(_g_) + SO_2(_g_)$

$K= \frac{[CO_2][SO_2]}{[O_2]}$

Question 3

The correct answer is c

In a molecule the oxidation number are assigned to get the sum of a neutral charge or ion. The overall charge of $SO_4^2^-$ is -2 and in all its compounds oxygen has -2 charge, hence

$S+ 4O = -2\\S+4(-2)=-2\\\implies S= -2 +8 = +6$

Question 4

The correct answer is b. An oxidising agent must gain electrons in a reaction, thus it is the one that undergoes reduction.In order find out what is being reduced we write half reactions for molecules that change their state. $Ag^+$ and $K^+$ are spectactor ions in this reaction.

$Cl_2 + 2e \implies 2Cl^-\\\\NO_2 +H_2O \implies NO_3 +2H^+ +2e\\\\H^+ + OH^- \implies H_2O\\$

In the chloride half reaction $Cl_2$ gains electrons to become $Cl^-$ ions.

Question 5

The last element D is correct. When a nucleus decays by beta emission it produces a daughter nucleus that has same mass number but different atomic number. Therefore beta-decay will have equation

$\frac{187}{75} Re \implies \frac{187}{76} Os + \beta$

Question 6

The correct answer is a. A beta particle is an electron because it has a charge of -1 and has same mass as an electron, while a positron is a particle with the same mass as an electron but with a positive charge.

4 0

3 years ago

Why are concentration units of mole fraction used in some colligative properties calculations?

Alja [10]

The answer is d. mole fraction is not affected by changes in temperature. The colligative properties is only depend on the number of the solute in the solvent.

4 0

3 years ago

Which arrows represents the phase transitions in which he's energy is gained

prisoha [69]

Answer:

Do you have a picture of this?

6 0

3 years ago