All categories

3 years ago

Among the following which are represent polyatomic molecule.A.H2 B.He C.N2 D.P4 which one

Chemistry

1 answer:

olga2289 [7]3 years ago

6 0

Answer:

Explanation:

P4 is polyatomic molecule

You might be interested in

Why is it difficult to hold and keep liquids like water in your hand? Guys please help

Zanzabum

Answer:

Molecules move freely around since they don't have a definite shape. This is the reason water stays liquid and couldn't be gripped.

5 0

3 years ago

The law of conservation of mass states that mass is neither created nor destroyed during a chemical reaction. This can be gleane

GenaCL600 [577]

Answer : The total mass of oxygen gas released in the reaction will be, 12.8 grams

Explanation :

Law of conservation of mass : It states that mass can neither be created nor be destroyed but it can only be transformed from one form to another form.

This also means that total mass on the reactant side must be equal to the total mass on the product side.

The balanced chemical reaction will be,

$2MgO\rightarrow 2Mg+O_2$

According to the law of conservation of mass,

Total mass of reactant side = Total mass of product side

Total mass of $2MgO$ = Total mass of $2Mg+O_2$

or,

Total mass of $2MgO$ = Mass of $2Mg$ + Mass of $O_2$

As we are given :

Total mass of $MgO$ = 16.12 grams

The mass of $Mg$ = 9.72 grams

So,

Total mass of $2MgO$ = Mass of $2Mg$ + Mass of $O_2$

$2\times 16.12g=2\times 9.72g+\text{Mass of }O_2$

$\text{Mass of }O_2=32.24g-19.44g=12.8g$

Therefore, the total mass of oxygen gas released in the reaction will be, 12.8 grams

8 0

3 years ago

20cm of 0.09M solution of H2SO4. requires 30cm of NaOH for complete neutralization. Calculate the

kirill115 [55]

Answer:

Choice A: approximately $0.12\; \rm M$ .

Explanation:

Note that the unit of concentration, $\rm M$ , typically refers to moles per liter (that is: $1\; \rm M = 1\; \rm mol\cdot L^{-1}$ .)

On the other hand, the volume of the two solutions in this question are apparently given in $\rm cm^3$ , which is the same as $\rm mL$ (that is: $1\; \rm cm^{3} = 1\; \rm mL$ .) Convert the unit of volume to liters:

$V(\mathrm{H_2SO_4}) = 20\; \rm cm^{3} = 20 \times 10^{-3}\; \rm L = 0.02\; \rm L$ .
$V(\mathrm{NaOH}) = 30\; \rm cm^{3} = 30 \times 10^{-3}\; \rm L = 0.03\; \rm L$ .

Calculate the number of moles of $\rm H_2SO_4$ formula units in that $0.02\; \rm L$ of the $0.09\; \rm M$ solution:

$\begin{aligned}n(\mathrm{H_2SO_4}) &= c(\mathrm{H_2SO_4}) \cdot V(\mathrm{H_2SO_4})\\ &= 0.02 \; \rm L \times 0.09 \; \rm mol\cdot L^{-1} = 0.0018\; \rm mol \end{aligned}$ .

Note that $\rm H_2SO_4$ (sulfuric acid) is a diprotic acid. When one mole of $\rm H_2SO_4$ completely dissolves in water, two moles of $\rm H^{+}$ ions will be released.

On the other hand, $\rm NaOH$ (sodium hydroxide) is a monoprotic base. When one mole of $\rm NaOH$ formula units completely dissolve in water, only one mole of $\rm OH^{-}$ ions will be released.

$\rm H^{+}$ ions and $\rm OH^{-}$ ions neutralize each other at a one-to-one ratio. Therefore, when one mole of the diprotic acid $\rm H_2SO_4$ dissolves in water completely, it will take two moles of $\rm OH^{-}$ to neutralize that two moles of $\rm H^{+}$ produced. On the other hand, two moles formula units of the monoprotic base $\rm NaOH$ will be required to produce that two moles of $\rm OH^{-}$ . Therefore, $\rm NaOH$ and $\rm H_2SO_4$ formula units would neutralize each other at a two-to-one ratio.

$\rm H_2SO_4 + 2\; NaOH \to Na_2SO_4 + 2\; H_2O$ .

$\displaystyle \frac{n(\mathrm{NaOH})}{n(\mathrm{H_2SO_4})} = \frac{2}{1} = 2$ .

Previous calculations show that $0.0018\; \rm mol$ of $\rm H_2SO_4$ was produced. Calculate the number of moles of $\rm NaOH$ formula units required to neutralize that

$\begin{aligned}n(\mathrm{NaOH}) &= \frac{n(\mathrm{NaOH})}{n(\mathrm{H_2SO_4})}\cdot n(\mathrm{H_2SO_4}) \\&= 2 \times 0.0018\; \rm mol = 0.0036\; \rm mol\end{aligned}$ .

Calculate the concentration of a $0.03\; \rm L$ solution that contains exactly $0.0036\; \rm mol$ of $\rm NaOH$ formula units:

$\begin{aligned}c(\mathrm{NaOH}) &= \frac{n(\mathrm{NaOH})}{V(\mathrm{NaOH})} = \frac{0.0036\; \rm mol}{0.03\; \rm L} = 0.12\; \rm mol \cdot L^{-1}\end{aligned}$ .

3 0

3 years ago

Margret claimed that she needed 5.45 moles of Potassium Chloride, KCl to complete her experiment. How many grams of KCl does she

zubka84 [21]

Answer:

loiuygfcx

Explanation:

3 0

3 years ago

If a mole of sodium chloride weighs approximately 58 grams, and you have 29 grams of sodium chloride, how many moles of sodium c

Dennis_Churaev [7]

Molar mass NaCl = 58 g

Mass of solute = 29 g

number of moles: mass of solute / molar mass

n = 29 / 58

n = 0.5 moles

hope this helps!

4 0

3 years ago

Among the following which are represent polyatomic molecule.A.H2 B.He C.N2 D.P4 which one ​

Among the following which are represent polyatomic molecule.A.H2 B.He C.N2 D.P4 which one