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3 years ago

Hey! Could someone explain how to do this? Thanks!

Chemistry

1 answer:

Aleksandr [31]3 years ago

4 0

Answer:

Explanation:

The compounds XCl₂ and X₃N₂ shows that the valency of X is 2. If they are ionic compounds then X is a metal. The metals having valency=2 mostly reside in group-2. Exapmle: MgCl₂ and Mg₃N₂.

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You are given 600 grams of sodium chloride (NaCl), but you are planning to purify the substance and extract just the sodium. How

Eddi Din [679]

Answer:

236.02 grams of Na is produced by 600g of NaCl.

Explanation:

NaCl --> Na+Cl-

to find the number of moles NaCl has, divide the grams over the molar mass which is 600/58.44

number of moles of nacl= 10.2 moles

then turn moles back to grams which is moles x molar mass

10.2 moles x 22.9 mass

= 236.02 grams

4 0

3 years ago

Trimethylamine, (CH3)3N is a weak base (Kb = 6.3 × 10–5). What volume of this gas, measured at STP, must be dissolved in 2.5 Lof

9966 [12]

Answer:

8.9L is the volume of the gas that must be dissolved.

Explanation:

For a weak base, we can find [(CH₃)₃N] using the equation:

Kb = [OH⁻] [[(CH₃)₃NH⁺] / [(CH₃)₃N]

As [OH⁻] = [[(CH₃)₃NH⁺] and [OH⁻] = 10^-pOH = 3.16x10⁻³M:

6.3x10⁻⁵ = [3.16x10⁻³M][3.16x10⁻³M] / [(CH₃)₃N]

[(CH₃)₃N] = 0.1587M

As the volume is 2.5L, moles are:

2.5L * (0.1587mol / L) = 0.3968moles

Using:

PV = nRT

We can solve for volume of the gas as follows:

P = 1atm at STP; n = 0.3968moles; R = 0.082atmL/molK; T = 273.15K at STP

V = 0.3968mol*0.082atmL/molK*273.15K/1atm

V = 8.9L is the volume of the gas that must be dissolved.

3 0

3 years ago

A chemical reaction that has a positive δg is best described as

Alina [70]

Answer:

Explanation:

endergonic

A chemical reaction that has a positive ΔG is correctly described as A) endergonic.

5 0

4 years ago

Stars, such as our sun, use fusion to combine hydrogen atoms into helium atoms, and in the process, create energy. As massive st

Zinaida [17]

Hey there! The answer to your first question is SILICON, Nickle has 28 protons, silicon has 14, 14+14=28. Its the only element thats adds up. I dont know about the 2nd one myself.

4 0

3 years ago

Part A: Three gases (8.00 g of methane, CH_4, 18.0g of ethane, C_2H_6, and an unknown amount of propane, C_3H_8) were added to t

myrzilka [38]

Explanation:

Part A:

Total pressure of the mixture = P = 5.40 atm

Volume of the container = V = 10.0 L

Temperature of the mixture = T = 23°C = 296.15 K

Total number of moles of gases = n

PV = nRT (ideal gas equation)

$n=\frac{PV}{RT}=\frac{5.40 atm\times 10.0 L}{0.0821 atm L/mol K\times 296.15 K}=2.22 mol$

Moles of methane gas = $n_1=\frac{8.00 g}{16 g/mol}=0.5 mol$

Moles of ethane gas = $n_2=\frac{18.0 g}{30 g/mol}=0.6 mol$

Moles of propane gas = $n_3$

$n=n_1+n_2+n_3$

$2.22=0.5 mol +0.6 mol+ n_3$

$n_3= 2.22 mol - 0.5 mol -0.6 mol= 1.12 mol$

Mole fraction of methane = $\chi_1=\frac{n_1}{n_1+n_2+n_3}=\frac{n_1}{n}$

$\chi_1=\frac{0.5 mol}{2.22 mol}=0.2252$

Similarly, mole fraction of ethane and propane :

$\chi_2=\frac{n_2}{n}=\frac{0.6 mol}{2.22 mol}=0.2703$

$\chi_3=\frac{n_3}{n}=\frac{1.12 mol}{2.22 mol}=0.5045$

Partial pressure of each gas can be calculated by the help of Dalton's' law:

$p_i=P\times \chi_1$

Partial pressure of methane gas:

$p_1=P\times \chi_1=5.40 atm\times 0.2252=1.22 atm$

Partial pressure of ethane gas:

$p_2=P\times \chi_2=5.40 atm\times 0.2703=1.46 atm$

Partial pressure of propane gas:

$p_3=P\times \chi_3=5.40 atm\times 0.5045=2.72 atm$

Part B:

Suppose in 100 grams mixture of nitrogen and oxygen gas.

Percentage of nitrogen = 37.8 %

Mass of nitrogen in 100 g mixture = 37.8 g

Mass of oxygen gas = 100 g - 37.8 g = 62.2 g

Moles of nitrogen gas = $n_1=\frac{37.8 g g}{28g/mol}=1.35 mol$

Moles of oxygen gas = $n_2=\frac{62.2 g}{32 g/mol}=1.94 mol$

Mole fraction of nitrogen= $\chi_1=\frac{n_1}{n_1+n_2}$

$\chi_1=\frac{1.35 mol}{1.35 mol+1.94 mol}=0.4103$

Similarly, mole fraction of oxygen

$\chi_2=\frac{n_2}{n_1+n_2}=\frac{1.94 mol}{1.35 mol+1.94 mol}=0.5897$

Partial pressure of each gas can be calculated by the help of Dalton's' law:

$p_i=P\times \chi_1$

The total pressure is 405 mmHg.

P = 405 mmHg

Partial pressure of nitrogen gas:

$p_1=P\times \chi_1=405 mmHg\times 0.4103 =166.17 mmHg$

Partial pressure of oxygen gas:

$p_2=P\times \chi_2=405 mmHg\times 0.5897=238.83 mmHg$

3 0

3 years ago