Which of the following is a mixture of substances?

A solution is formed by mixing 15.2 g KOH into

nikitadnepr [17]

Answer:

There are approximately $0.271\; \rm mol$ of formula units in that $\rm 15.2\; g$ of $\rm KOH$ (the solute of this solution.)

Explanation:

A solution includes two substances: the solute and the solvent. Note the solution here contains significantly more water than $\rm KOH$ . Hence, assume that water is the solvent (as it is in many other solutions.)

The (molar) formula mass of $\rm KOH$ is necessary for finding the number of moles of

One $\rm K$ atom,
One $\rm O$ atom, and
One $\rm H$ atom.

The formula mass of $\rm KOH$ will thus be the sum of:

The mass of one mole of $\rm K$ atoms,
The mass of one mole of $\rm O$ atoms, and
The mass of one mole of $\rm H$ atoms.

On the other hand, the mass (in grams) of one mole of atoms of an element is (numerically) the same as its relative atomic mass. The relative atomic mass data can be found on most modern periodic tables.

Relative atomic mass data from a modern periodic table:

$\rm K$ : $39.098$ .
$\rm O$ : $15.999$ .
$\rm H$ : $1.008$ .

For example, the relative atomic mass of $\rm K$ (potassium, atomic number $19$ ) is $39.098$ (3 sig. fig.) Hence, the mass of one mole of

The formula mass of $\rm KOH$ is the sum of these three masses:

$\begin{aligned}& M(\mathrm{KOH}) \\ &\approx 39.098 + 15.999 + 1.008 \\ &= 56.105\; \rm g \cdot mol^{-1}\end{aligned}$ .

The number of moles of $\rm KOH$ formula units in this $15.2\; \rm g$ sample would be:

$\begin{aligned}n &= \frac{m(\mathrm{KOH})}{M(\mathrm{KOH})} \\ &\approx \frac{15.2\; \rm g}{56.105\; \rm g \cdot mol^{-1}} \approx 0.271\; \rm mol \end{aligned}$ .

6 0

3 years ago

How can an experiment support or fail support a hypothesis

melomori [17]

If a hypothesis is stated and outcome of the experiment is what was predicted, then it supports the hypothesis. if the experiment does not support the hypothesis, then the outcome was not what was predicted.

3 0

3 years ago

What is the specific heat of copper when heated to 221.32

Dafna1 [17]

Answer:

The specific heat of copper when heated to 221.32 (not listed form of heat measurement) is 221.32 (not listed form of heat measurement).

Explanation:

uh not really sure what else there is here, I may be missing something

5 0

3 years ago

What would happen to the water’s boiling point if MgSO4 is added to it?

kirill [66]

Answer:

When Epsom salt (magnesium sulfate) dissolves, it separates into its ions: a magnesium ion (Mg2+) and a sulfate ion (SO4 2-), which results in hard water. When hard water and soap are mixed, the magnesium ion reacts with soap molecules and forms a solid material called a precipitate, which does not dissolve.

Explanation:

can i have brainlest

4 0

3 years ago

How does the arrangement of elements in periods relate to electron configuration

VashaNatasha [74]

Electronic Configuration of elements in a period is same because If you see the electronic Configuration of elements in a period you will notice that the valence shell electrons for all elements are present in the same Shell. For example, in first period consisting of Hydrogen and Helium, both the elements' valence electrons are present in the same Shell.
Electronic Configuration of Hydrogen,
1s^1
Electronic Configuration of Helium,
1s^2

Both elements' valance electrons are present in the 1st shell

(This is just a small example to understand the concept because other periods are long but the first period is short that's why I gave the example of the first period)

4 0

3 years ago