All categories

4 years ago

Please I need it asap

Chemistry

2 answers:

DaniilM [7]4 years ago

5 0

Answer:

i think is A.

Explanation:

svp [43]4 years ago

4 0

Answer:

I not understand your questions

You might be interested in

Reactions that affect the nucleus of an atom are called

mylen [45]

Answer:

Nuclear Reactions.

7 0

3 years ago

A solution was prepared by dissolving 195.0 g of KCl in 215 g of water. Calculate the mole fraction of KCl. (The formula weight

defon

Answer:

Approximately $0.180$ .

Explanation:

The mole fraction of a compound in a solution is:

$\displaystyle \frac{\text{Number of moles of compound in question}}{\text{Number of moles of all particles in the solution}}$ .

In this question, the mole fraction of $\rm KCl$ in this solution would be:

$\displaystyle X_\mathrm{KCl} = \frac{n(\mathrm{KCl})}{n(\text{All particles in this soluton})}$ .

This solution consist of only $\rm KCl$ and water (i.e., $\rm H_2O$ .) Hence:

$\begin{aligned} X_\mathrm{KCl} &= \frac{n(\mathrm{KCl})}{n(\text{All particles in this soluton})}\\ &= \frac{n(\mathrm{KCl})}{n(\mathrm{KCl}) + n(\mathrm{H_2O})}\end{aligned}$ .

From the question:

Mass of $\rm KCl$ : $m(\mathrm{KCl}) = 195.0\; \rm g$ .
Molar mass of $\rm KCl$ : $M(\mathrm{KCl}) = 74.6\; \rm g \cdot mol^{-1}$ .

Mass of $\rm H_2O$ : $m(\mathrm{H_2O}) = 215\; \rm g$ .
Molar mass of $\rm H_2O$ : $M(\mathrm{H_2O}) = 18.0\; \rm g\cdot mol^{-1}$ .

Apply the formula $\displaystyle n = \frac{m}{M}$ to find the number of moles of $\rm KCl$ and $\rm H_2O$ in this solution.

$\begin{aligned}n(\mathrm{KCl}) &= \frac{m(\mathrm{KCl})}{M(\mathrm{KCl})} \\ &= \frac{195.0\; \rm g}{74.6\; \rm g \cdot mol^{-1}} \approx 2.61\; \em \rm mol\end{aligned}$ .

$\begin{aligned}n(\mathrm{H_2O}) &= \frac{m(\mathrm{H_2O})}{M(\mathrm{H_2O})} \\ &= \frac{215\; \rm g}{18.0\; \rm g \cdot mol^{-1}} \approx 11.9\; \em \rm mol\end{aligned}$ .

The molar fraction of $\rm KCl$ in this solution would be:

$\begin{aligned} X_\mathrm{KCl} &= \frac{n(\mathrm{KCl})}{n(\text{All particles in this soluton})}\\ &= \frac{n(\mathrm{KCl})}{n(\mathrm{KCl}) + n(\mathrm{H_2O})} \\ &\approx \frac{2.61 \; \rm mol}{2.61\; \rm mol + 11.9\; \rm mol} \approx 0.180\end{aligned}$ .

(Rounded to three significant figures.)

8 0

3 years ago

The balanced equation for the combustion of Hexane,C6H14 , is

shusha [124]

Answer:

$2C _{6}H _{14} + 19O _{2}→12CO _{2} +14H _{2} O$

3 0

3 years ago

QUESTION 4

Greeley [361]

Answer:

B) 2

Explanation:

There are two significant figures in given measurement,

2, 0

Significant figures:

1= The given measurement have four significant figures 1534.

2= All non-zero digits are consider significant figures like 1, 2, 3, 4, 5, 6, 7, 8, 9.

3= Leading zeros are not consider as a significant figures. e.g. 0.03 in this number only one significant figure present which is 3.

4= Zero between the non zero digits are consider significant like 107 consist of three significant figures.

5= The zeros at the right side e.g 2400 are also significant. There are four significant figures are present.

7 0

4 years ago

A boat sails into a bay and drops anchor. Several hours later, it is surrounded by mud. What

WARRIOR [948]

Answer:

the flow of the water pushed the mud around the anchor

Explanation:

4 0

3 years ago