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3 years ago

A mole of any substance contains ___ particles.

1 answer:

7 0

One mole of a substance is equal to 6.022 × 10²³ units of that substance (such as atoms, molecules, or ions). The number 6.022 × 10²³ is known as Avogadro's number or Avogadro's constant.

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Define galvanization

boyakko [2]

Answer:

Galvanization or galvanizing is the process of applying a protective zinc coating to steel or iron, to prevent rusting. The most common method is hot-dip galvanizing, in which the parts are submerged in a bath of molten hot zinc.

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4 years ago

Dissolve 7, 8 grams of Mg and Al mixture with excess HCl solution. After the reaction, the mass of acid solution increased by 7,

fgiga [73]

Answer:

Mg = 2,5 g; Al = 5,3 g

Explanation:

1) Reactions

Mg + 2HCl ⟶ MgCl₂ + H₂

2Al + 6HCl ⟶ 2AlCl₃ + 3H₂

2) Mass of each metal

If there had been no reaction, the mass of the solution would have increased by 7,8 g.

The mass increased by only 7,0 g.

The missing 0,8 g must represent the mass of the hydrogen generated by the reaction.

We have two relations:

Mass of Mg + mass of Al = 7,8 g

H₂ from Mg + H₂ from Al = 0,8 g

i) Calculate the moles of H₂

$n = \text{0,8 g H}_{2} \times \dfrac{\text{1 mol H}_{2}}{\text{2,016 g H}_{2}} = \text{0.40 mol H}_{2}$

(ii) Solve the relationship

Let x = mass of Mg. Then

7,8 - x = mass of Al

Moles of Mg = x/24.30

Moles of Al = (7,8 - x)/26.98

Moles of H₂ from Mg = (1/1) × moles of Mg = 1 × (x/24,30) = 0,0412x

Moles of H₂ from Al = (3/2) × Moles of Al = 1.5(7,8 - x)/26,98 = (11,7 -1,5x)/26,98

$\begin{array}{rcl}0,0412x + \dfrac{ 11,7 - 1,5x }{26,98} &= &0,40\\\\ 1,11x + 11.7 - 1,5x &=& 10.7\\-0.39x& = &-1.0\\x &=& \text{2.5 g}\\\end{array}$

Mass of Mg = 2,5 g

Mass of Al = 7,8 g - 2,5 g = 5,3 g

The masses of the metals are Mg = 2,5 g; Al = 5,3 g

6 0

3 years ago

Which show how the properties of the two objects compare? A. temperature and total kinetic energy are different. B. Thermal ener

alexandr402 [8]

A, i think, I'm not 100 on that

4 0

4 years ago

Read 2 more answers

Kinetic energy is energy of motion. What below is considered to be a form of kinetic energy?

gregori [183]

Answer:

In physics, the kinetic energy of an object is the energy that it possesses due to its motion It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity Having gained this energy during its acceleration the body maintains this kinetic energy unless its speed changes

Example:

A semi-truck travelling down the road

A river flowing at a certain speed

5 0

3 years ago

Fernando places 50 mL of HCl in a 100 mL beaker and 50 mL of NaOH in a 100 mL beaker. he places them on a scale together and mea

olchik [2.2K]

Answer:

The correct options are:

B. The HCl is the solute.

D. The H₂O is the solvent.

E. This mixture conducts electricity.

Explanation:

For the preparation of the HCl solution, 10 mL of HCl and 40 mL of water were mixed.

The compound that is present in the solution in a smaller ratio is the solute and the other compount -present in higher ratio- is the solvent.

So, the solute is HCl and the solvent is water (H₂O). Furthermore, water is considered as an universal solvent (for most of the polar and ionic compounds). According to this, the following options are correct:

B. The HCl is the solute.

D. The H₂O is the solvent.

Then, a condition for a solution that is able to conduct electricity is the presence of ions in the solution. When HCl is dissolved in water, it dissociates in ions according to the following equilibrium:

HCl ⇔ H⁺ + Cl⁻

The ions H⁺ and Cl⁻ are electrically charged so the solution can conduct electricity. According to this, the following option is also correct:

E. This mixture conducts electricity.

7 0

3 years ago