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2 years ago

Why are sodium (Na) and potassium (K) in the same group on the periodic table?

Chemistry

1 answer:

Artyom0805 [142]2 years ago

7 0

Explanation:

Sodium and potassium are in the same group on the periodic table because they both have similar number of valence electrons (1 electron) in their shells

Na = 2,8,1

K = 2,8,8,1

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48g LiOH dissolved in 1.0 L of solution. calculate the molarity

KatRina [158]

48g LiOH/ 23.95g = 2.0041 moles
Molarity= Mole of solute / liter of solution

Molarity= 2.0041 M
Molarity = 2.0 M

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3 years ago

Why is the piece of coal layered?

marysya [2.9K]

Answer:

Coal is layered because it is a type of sedimentary rock

Explanation:

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3 years ago

. The Henry's law constant for helium gas in water at 30 ∘C is 3.7×10−4M/atm; the constant for N2 at 30 ∘C is 6.0×10−4M/atm. a.

ludmilkaskok [199]

Explanation:

1) Henry's law states that the amount of gas dissolved or molar solubility of gas is directly proportional to the partial pressure of the liquid.

To calculate the molar solubility, we use the equation given by Henry's law, which is:

$M_{g}=K_H\times p_{g}$

where,

$K_H$ = Henry's constant

$p_{He}$ = partial pressure of gas

a) $K_H=3.7\times 10^{-4} M/atm$

$p_{He}=2.1 atm$

Putting values in above equation, we get:

$M_{He}=3.7\times 10^{-4} M/atm\times 2.1 atm = 7.77\times 10^{-4} M$

The solubility of helium gas is $7.77\times 10^{-4} M$

b) $K_H=6.0\times 10^{-4} M/atm$

$p_{N_2}=2.1 atm$

Putting values in above equation, we get:

$M_{He}=6.0\times 10^{-4} M/atm\times 2.1 atm = 1.26\times 10^{-3} M$

The solubility of nitrogen gas is $1.26\times 10^{-3} M$

a) Mass of solute or methanol , m= 14.7 g

Mass of solvent or water , m'= 186 g

Mass of the solution = M = m + m' = 14.7 g + 186 g = 200.7 g

$w/w\%=\frac{\text{Mass of solute}}{\text{Mass of solution}}\times 100$

$=\frac{14.7 g}{200.7 g}\times 100=7.32\%$

The mass percent of methanol is 7.32%.

b) Molality is defined as moles of solute per kilograms of solvent.

$m=\frac{\text{Moles of solute}}{\text{Mass of solvent in kg}}$

Moles of methanol = $\frac{14.7 g}{32 g/mol}=0.4594 mol$

Mass of solvent = 186 g = 0.186 kg

$m=\frac{0.4594 mol}{0.186 kg}=2.4610 mol/kg$

The molality of methanol is 2.4610 mol/kg.

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3 years ago

uranmaximum [27]

Answer:

Oxygen atoms form two double bonds in silicon(IV) oxide.

Silicon(IV) oxide has a high melting point.

Explanation:

Silicon dioxide is structurally analogous to carbon dioxide in the sense that it also contains two oxygen atoms that are double bonded to silicon the central atom in the molecule.

Silicon dioxide has a very high melting point of about 1710 degrees centigrade because of its large macromolecular structure which requires much energy to break such intermolecular interactions.

8 0

3 years ago

Identify the effect of increasing acidity on the solubility of the given compounds. Drag the appropriate items to their respecti

PIT_PIT [208]

Answer:

Ca3(PO4)2- Increase in solubility

Barium hydroxide- increase in solubility

Magnesium carbonate- increase in solubility

Copper II sulphide- increase solubility

Lead II bromide- increase solubility

CuI - increase solubility

Explanation:

Calcium phosphate solubility is pH dependent. At lower pH, calcium phosphate is more soluble in water while at pH above 8.5, the solubility of calcium phosphate decreases markedly.

For Barium hydroxide and magnesium carbonate,decreasing the pH will increase the solubility of the compound.

For copper II sulphide,decreasing the pH will lead to a greater solubility. Also, lead II bromide is ordinarily insoluble in water but it's solubility increases with decreasing pH.

CuI is insoluble in water but soluble in dilute hydrochloric acid.

6 0

3 years ago

Why are sodium (Na) and potassium (K) in the same group on the periodic table?​

Why are sodium (Na) and potassium (K) in the same group on the periodic table?