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2 years ago

Help please it's due in 12 hours (20 points)

Chemistry

1 answer:

Rufina [12.5K]2 years ago

8 0

Answer:

1) K and Rb

2) 20 protons, 20 neutrons, and 20 electrons.

Explanation:

1) If it's in the same column, it has the same # of valence electrons (e- on the outer shell), therefore similar chemical properties.

1) atomic #, 20, is the number of protons

2) subtract the mass number from # of protons, which you get 20 neutrons

3) Number of electrons in a neutral atom = number of electrons, which is 20. You can also check yourself by looking at electron configuration on a full periodic table.

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A 0.590 gram sample of a metal, M, reacts completely with sulfuric acid according to:

Naddik [55]

Answer:

Molar mass of the metal = 59.0 g/mol

Explanation:

Vapor pressure of water at $25^oC$ = 23.78 torr

We are given:

Total vapor pressure = 756.0 torr

Vapor pressure of hydrogen gas = Total vapor pressure - Vapor pressure of water = (756.0 - 23.78) torr = 732.22 torr

To calculate the amount of hydrogen gas collected, we use the equation given by ideal gas which follows:

$PV=nRT$

where,

P = pressure of the gas = 732.22 torr

V = Volume of the gas = 255 mL = 0.255 L ( 1 mL = 0.001 L )

T = Temperature of the gas = $25^oC=[25+273]K=298K$

R = Gas constant = $62.3637\text{ L.torr }mol^{-1}K^{-1}$

n = number of moles of hydrogen gas = ?

Putting values in above equation, we get:

$732.22 torr\times 0.255L=n\times 62.3637\text{ L.torr }mol^{-1}K^{-1}\times 298K\\\\n=\frac{732.22\times 0.255}{62.3637\times 298}=0.01mol$

From the reaction shown below:-

$M+H_2SO_4\rightarrow MSO_4+H_2$

1 mole of hydrogen gas is produced when 1 mole of the metal is reacted.

Also,

0.01 mole of hydrogen gas is produced when 0.01 mole of the metal is reacted.

Moles of the metal = 0.01 mol

Mass taken = 0.590 g

The formula for the calculation of moles is shown below:

$moles = \frac{Mass\ taken}{Molar\ mass}$

Thus,

$0.01\ mole= \frac{0.590\ g}{Molar\ mass}$

Molar mass of the metal = 59.0 g/mol

5 0

4 years ago

Read 2 more answers

What is the molarity of a solution prepared by dissolving 36. 0 g of naoh in enough water to make 1. 50 l of solution?

Vlada [557]

0.6 mol / L is the molarity of a solution prepared by dissolving 36. 0 g of NaOH in enough water to make 1. 50 l of solution.

The amount of a substance in a specific volume of solution is known as its molarity (M). The number of moles of a solute per liter of a solution is known as molarity. The molar concentration of a solution is another term for molarity.

The ratio employed to indicate the solution's concentration is called its molarity. Understanding a solution's molarity is important since it allows you to determine the actual concentration as well as whether the solution is diluted or concentrated.

Amount of NaOH = 36. 0 g

Amount of water = 1. 50 L

1 mol of NaOH = 40 g,

Moles of NaOH = 36. 0 / 40 g = 0.9 mol NaOH

Molarity of a solution = moles of solute / Liters of solution

Molarity of a solution = 0.9 / 1.50

Molarity of a solution = 0.6 mol / L

To know more about Molarity refer to: brainly.com/question/8732513

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4 0

1 year ago

For every action there is an equal and opposite reaction is known as? *