Plz!!!!!!!!!!!!!!!!! name the given substances and calculate their molecular mass

Which of the following will lose 2 electrons to become stable?

Softa [21]

Answer:

Magnesium,Berillium,

Explanation:

they they belong to group II

8 0

3 years ago

What are the half-reactions for a galvanic cell with aluminum and gold electrodes?

lawyer [7]

Answer:

A

Explanation:

In a galvanic cell, energy is produced by spontaneous chemical processes.

The cathode and anode of this cell will depend on the relative position of the two metals in the electrochemical series.

Aluminium is higher in the electrochemical series so aluminium will be the anode. Silver is lower in the electrochemical series so silver will be the cathode.

Recall that oxidation (electron loss) occurs at the anode while reduction (electron gain) occurs at the cathode.

8 0

3 years ago

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The reusable booster rockets of the U.S. space shuttle use a mixture of aluminum and ammonium perchlorate for fuel. A possible e

Klio2033 [76]

Answer:

0.2298kg of Al

Explanation:

From the equation of reaction

3 moles of Al (81g) is required to mix with 3 moles of NH4ClO4 (352.5g)

Mass of Al required in the fuel mixture for every kilogram (1000g) of NH4ClO4 = 1000×81/352.5 = 229.8g = 229.8/1000 = 0.2298kg

3 0

3 years ago

Melting ice off a windshield is which change

Marianna [84]

Answer:

Physical Change

Explanation:

The ice isn't changing what it is, because its still water (even though its in a different form) If you freeze it again it will be exactly the same and so its a Physical Change

8 0

3 years ago

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2. A solution is made by adding 1.23 mol of KCl to 1000.0 g of water. Assume that the

ladessa [460]

Answer:

a. 74.55 g/mol.

b. 91.70 g.

c. 8.40%.

d. 1.23 mol/L.

Explanation:

a. Calculate the formula weight of KCl.

∵ Formula weight of KCl = atomic weight of K + atomic weight of Cl

atomic weight of K = 39.098 g/mol, atomic weight of Cl = 35.45 g/mol.

∴ Formula weight of KCl = atomic weight of K + atomic weight of Cl = 39.098 g/mol + 35.45 g/mol = 74.548 g/mol ≅ 74.55 g/mol.

b. Calculate the mass of KCl in grams.

we can use the relation:

no. of moles (n) = mass/molar mass.

∴ mass of KCl = n*molar mass = (1.23 mol)*(74.55 g/mol) = 91.69 g ≅ 91.70 g.

c. Calculate the percent by mass of KCl in this solution.

The mass % of KCl = (mass of KCl/mass of the solution) * 100.

mass of KCl = 91.70 g,

mass of the solution = 1000.0 g of water + 91.70 g of KCl = 1091.70 g.

∴ The mass % of KCl = (91.70 g/1091.70 g)*100 = 8.399% ≅ 8.40%.

d. Calculate the molarity of the solution.

Molarity is the no. of moles of solute per 1.0 L of the solution.

M = (no. of moles of KCl)/(Volume of the solution (L))

no. of moles of KCl = 1.23 mol,

Volume of the solution = mass of water / density of water = (1000.0 g)/(1.00 g/mL) = 1000.0 mL = 1.0 L.

M = (1.23 mol)/(1.0 L) = 1.23 mol/L.

3 0

4 years ago