6. Steel is a metallic-like material but it is not a pure element. It is a alloy.

Whats the formula for mass

s2008m [1.1K]

Answer:

The unit of molar mass is kg/mol. Where, m = mass, v = velocity.

Hope that helps :)

5 0

3 years ago

Which characteristic of O₂ is correct?

barxatty [35]

Answer:

One mole of O₂ weighs 32 g

Explanation:

5 0

2 years ago

Small quantites of hydrogen gas can be prepared in the laboratory by the addition of aqueous hydrochloric acid to metallic zinc.

ira [324]

Answer: The mass or zinc reacted is 0.624 grams.

Explanation:

We are given:

Total pressure = 1.032 atm

Vapor pressure of water = 32 torr = 0.042 atm (Conversion factor: 1 atm = 760 torr)

To calculate partial pressure of hydrogen gas, we use the equation:

$p_{H_2}=p_T-p_{H_2O}\\\\p_{H_2}=1.032-0.042=0.99atm$

To calculate the number of moles of hydrogen gas, we use the equation given by ideal gas follows:

$PV=nRT$

where,

P = pressure of hydrogen gas = 0.99 atm

V = Volume of hydrogen gas = 240. mL = 0.240 L (Conversion factor: 1 L = 1000 mL)

T = Temperature of hydrogen gas = $30^oC=[30+273]K=303K$

R = Gas constant = $0.0821\text{ L. atm }mol^{-1}K^{-1}$

n = number of moles of hydrogen gas = ?

Putting values in above equation, we get:

$0.99atm\times 0.240L=n\times 0.0821\text{ L atm }mol^{-1}K^{-1}\times 303K\\n=\frac{0.99\times 0.240}{0.0821\times 303}=9.55\times 10^{-3}mol$

The chemical equation for the reaction of zinc and hydrochloric acid follows:

$Zn+2HCl\rightarrow ZnCl_2+H_2$

By Stoichiometry of the reaction:

1 mole of hydrogen gas is produced from 1 mole of zinc metal

So, $9.55\times 10^{-3}mol$ of hydrogen gas is produced from = $\frac{1}{1}\times 9.55\times 10^{-3}=9.55\times 10^{-3}mol$ of zinc metal

To calculate the mass of zinc metal, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

Molar mass of zinc = 65.38 g/mol

Moles of zinc = $9.55\times 10^{-3}$ moles

Putting values in above equation, we get:

$9.55\times 10^{-3}mol=\frac{\text{Mass of zinc}}{65.38g/mol}\\\\\text{Mass of zinc}=(9.55\times 10^{-3}mol\times 65.38g/mol)=0.624g$

Hence, the mass or zinc reacted is 0.624 grams.

4 0

3 years ago

A certain weak acid, ha, has a ka value of 3.6×10−7. part a calculate the percent ionization of ha in a 0.10 m solution. express

slega [8]

Answer is: the percent ionization is 0,19%.
Chemical reaction: HA(aq) ⇄ H⁺(aq) + A⁻(aq).
Ka(HA) = 3,6·10⁻⁷.
c(HA) = 0,1 M.
[H⁺] = [A⁻] = x; equilibrium concentration.
[HA] = 0,1 M - x.
Ka = [H⁺] · [A⁻] / [HA].
0,00000036 = x² / 0,1 M - x.
Solve quadratic equation: x = 0,00019 M.
α = 0,00019 M ÷ 0,1 M · 100% = 0,19%.

8 0

3 years ago

the average speeds of gas molecules in.cylinders A,b,c,d are 0.01 m/s, 0.005m/s ,0.1 m/s and 0.5 m/s, respectively .which cylind

Darya [45]

The average speed of the gas is related to the kinetic energy of the gas. The kinetic energy of the gas is also related to the temperature of the gas. If the average speed of the gas is closer to zero, it means that it has very low motion or kinetic energy. This can be inferred that the gas has a very low temperature. At absolute zero, the motion of all the gas molecules stops. This means that the kinetic energy of the gas is also zero. Zero kinetic energy means zero average speed. So, the answer is cylinder B. The average speed of the gas in cylinder B is closest to zero.

8 0

3 years ago