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3 years ago

Which element is classified as an alkali metal?

2 answers:

4 0

The alkali metals are a group (column) in the periodic table consisting of the chemical elements lithium (Li), sodium (Na), potassium (K), [note 1] rubidium (Rb), caesium (Cs), [note 2] and francium (Fr).

dusya [7]3 years ago

3 0

Explanation:

All the elements of group 1 in the periodic table are known as alkali metals. These are lithium (Li), sodium (Na), potassium (K), rubidium (Rb), caesium (Cs), and francium (fr).

Characteristics of alkali metals are as follows.

Alkali metals are soft and can be cut with a knife.
They are good conductors of heat and electricity.
They have only 1 electron in their outermost sub-shell.
They are very reactive.
Alkali metals are ionic in nature.

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How many formula units are contained in 2.35mol of Iron (III) Oxide

konstantin123 [22]

Remember, 1 mole= 6.022x10^23 atoms, molecules, or formula units.

Answer is 1.42x10^24

7 0

3 years ago

A chemist dissolves 867. mg of pure barium hydroxide in enough water to make up 170. mL of solution. Calculate the pH of the sol

Ilya [14]

Answer: The pH of the solution is 11.2

Explanation:

Molarity of a solution is defined as the number of moles of solute dissolved per liter of the solution.

$Molarity=\frac{n\times 1000}{V_s}$

where,

n = moles of solute

$V_s$ = volume of solution in ml

moles of $Ba(OH)_2$ = $\frac{\text {given mass}}{\text {Molar mass}}=\frac{0.867g}{171g/mol}=0.00507mol$ (1g=1000mg)

Now put all the given values in the formula of molality, we get

$Molarity=\frac{0.00507\times 1000}{170}$

$Molarity=0.0298$

pH or pOH is the measure of acidity or alkalinity of a solution.

pH is calculated by taking negative logarithm of hydrogen ion concentration.

$pOH=-\log [OH^-]$

$Ba(OH)_2\rightarrow Ba^{2+}+2OH^{-}$

According to stoichiometry,

1 mole of $Ba(OH)_2$ gives 2 mole of $OH^-$

Thus 0.0298 moles of $Ba(OH)_2$ gives = $\frac{2}{1}\times 0.0298=0.0596$ moles of $OH^-$

Putting in the values:

$pOH=-\log[0.0596]=2.82$

$pH+pOH=14$

$pH=14-2.82$

$pH=11.2$

Thus the pH of the solution is 11.2

8 0

3 years ago

A compound contains sulfur, oxygen, and chlorine. Analysis shows that it contains by mass 26.95% sulfur and 59.61% chlorine. Wha

sladkih [1.3K]

Answer:

SCl₂

Explanation:

In order to know the empirical formula, we have to follow a series of steps.

Step 1: Divide each percentage by the atomic mass

S: 26.95/32.07 = 0.8403

Cl: 59.61/35.45 = 1.682

Step 2: Divide all the numbers by the smallest one.

S: 0.8403/0.8403 = 1

Cl: 1.682/0.8403 ≈ 2

The empirical formula of the compound is SCl₂.

7 0

3 years ago

Read 2 more answers

Which of the following is a homogenous mixture of two or more pure substances?

pashok25 [27]

The and is a alcohol

6 0

3 years ago

How many moles of Na2SO4 can be made with 7.28 mol of H2SO4?

Slav-nsk [51]

Answer:

7.28 mol Na2SO4

Explanation:

Since it is already in moles, all we have to do is use a molar ratio

A molar ratio is the proportions of reactants and products using the balanced equation. When writing a mole ratio, the given information must cross out with the right thing.

7.28 mol H2SO4 * 1 mol Na2SO4/1 H2SO4 = 7.28 mol Na2SO4

*notice how the H2SO4 crosses out

5 0

3 years ago