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3 years ago

How many valence electrons do the alkaline earth metals have?

Chemistry

2 answers:

fenix001 [56]3 years ago

5 0

Answer:

$\boxed{2}$

Explanation:

Alkaline earth metals are in group 2. The number of valence electrons of elements in group 2 is 2.

Vitek1552 [10]3 years ago

3 0

Hi there!

Answer:

Option B. 2.

-----------------

Alkaline earth metals consist of elements in group 2A of the periodic table, which contain 2 valence electrons.

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The pK of acetic acid is pK = 4.76. For a 0.1 M solution of acetic acid at a pH = 4.76 what is the concentration of [H+]?

spin [16.1K]

Answer:

[H+] = 1.74 x 10⁻⁵

Explanation:

By definition pH = -log [H+]

Therefore, given the pH, all we have to do is solve algebraically for [H+] :

[H+] = antilog ( -pH ) = 10^-4.76 = 1.74 x 10⁻⁵

6 0

3 years ago

if 28.5 g of calcium hydroxide is dissolved in enough water to make 185g of solution what is the percent by mass of calcium hydr

DENIUS [597]

The percent by mass of calcium hydroxide in the solution : 15.41%

<h3>Further explanation</h3>

The concentration of a substance can be expressed in several quantities such as moles, percent (%) weight/volume,), molarity, molality, parts per million (ppm) or mole fraction. The concentration shows the amount of solute in a unit of the amount of solvent.

Mass of solute (Ca(OH₂-Calcium hydroxide) : 28.5

Mass of solution = 185 g

$\tt \%mass=\dfrac{mass~solute}{mass~solution}\times 100\%\\\\\%mass=\dfrac{28.5~g}{185~g}\times 100\%\\\\\%mass=15.41\%$

6 0

2 years ago

You leave gasoline in an open can and it vaporizes. What type of change is this?

UNO [17]

Answer:evaporation

Explanation:

3 0

2 years ago

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Why is ocean water more dense than freshwater

zalisa [80]

A. Cuz it contains more salt
Hope this helps good luck on ur examsss :))))

8 0

3 years ago

State whether the sign of the entropy change expected for each of the following processes will be positive or negative, and expl

Strike441 [17]

Answer:

a) ΔS is negative

b) ΔS is positive

c) ΔS is positive

d) ΔS is negative

Explanation:

Entropy (S) is a thermodynamic parameter which measures the randomness or the disorder in a system. Greater the disorder more positive will be the value of entropy.

The extent of disorder increases as substances transition from the solid to the gaseous state. i.e.

S(solid) < S(liquid) < S(gas)

The entropy change for a given reaction is:

$\Delta S = S(products)-S(reactants)----(1)$

a) $PCl3(l) + Cl2(g) \rightarrow PCl5(s)$

Here the reactants are in the liquid and gas phase which have higher entropy than the product which is in the solid phase i.e. lower entropy.

Since S(product) < S(reactant), based on equation 1, ΔS will be negative.

b) $2HgO(s) \rightarrow 2Hg(l) + O2(g)$

Here the products are in the liquid and gas phase which have higher entropy than the reactant which is in the solid phase i.e. lower entropy.

Since S(product) > S(reactant), based on equation 1, ΔS will be positive.

c) $H2(g) \rightarrow 2H(g)$

Here the products and reactants are in the gas phase. However the number of moles of products is greater than the reactants

Since S(product) > S(reactant), based on equation 1, ΔS will be positive.

d) $U(s) + 3F2(g) \rightarrow UF6(s)$

Here one of the reactants is in the gas phase which corresponds to a more positive entropy compared to the product which is in the solid phase i.e. lower entropy.

Since S(product) < S(reactant), based on equation 1, ΔS will be negative.

8 0

2 years ago