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3 years ago

Three useful applications of alkaline earth metals

1 answer:

7 0

Alkaline earth metals refer to a group of elements in the periodic table. They include beryllium, magnesium, calcium, strontium, barium, and radium. Main uses of these elements are given below. Beryllium: It is used in small amounts to make copper beryllium alloy that are very strong and hard.

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Lauren has a big social studies test coming up. She knows that she needs to spread out her study sessions over a period of time.

tatuchka [14]

The study strategy Lauren is using in spreading her study sessions over a period of time is pacing, which helps the student develop a schedule focused on their own study pace.

<h3>Pacing Study Sessions</h3>

This study strategy of distributing the study into short sessions rather than studying the entire content through one long session is more effective in retaining content and learning.

What happens is that Lauren is using mass repetition processing, which can be compared to a longitudinal wave in physics, with spaces in between, concentrating the initial review close to the proof to ensure retention and avoid forgetting.

Through pacing, Lauren achieves greater motivation to carry out her studies in a concentrated and focused way, helping her to retain and preserve knowledge.

The correct answer is:

Pacing

Find out more information about pacing here:

brainly.com/question/988371

5 0

2 years ago

Consider the following reaction, which is spontaneous at room temperature. C3H8(g) + 5O2(g) → 3CO2(g) + 4H2O(g) Is ΔS positive o

Ugo [173]

Answer:

∆H = negative and ∆S = positive.

Explanation:

The reaction given in the question is spontaneous at room temperature ,

hence ,

The the gibbs free energy , i.e. ,∆G will be negative for spontaneous reaction

According to the formula ,

∆G = ∆H -T∆S

The value of ∆G can be negative , if ∆H has a negative value and ∆S has a positive value , because , T∆S , has a negative sign .

Hence , the answer will be , ∆H = negative and ∆S = positive.

3 0

3 years ago

A substance with a ph of 9 has

Arisa [49]

Answer:

c) more OH⁻ ions than H₃O⁺ ions

Explanation:

A substance with a PH of 9 implies that it has more OH⁻ ions than H₃O⁺ ions.

Such substances are said to be an alkaline or a base.

A base is a substance the produces excess hydroxyl ion in aqueous solutions.

An acid will produce excess hydroxonium ions in a solution.

So, the pH scale is used to indicate whether a substance is an acid or base or non of them.

Acids have pH of less than 7

Bases have pH of > 7

4 0

3 years ago

What is HC2H3O2 in science

Leona [35]

The chemical name of Hc2h3o2 is Acetic Acid.

3 0

3 years ago

Read 2 more answers

What is the vapor pressure of the solution if 35.0 g of water is dissolved in 100.0 g of ethyl alcohol at 25 ∘C? The vapor press

masya89 [10]

Answer: The vapor pressure of the solution is 43.55 mmHg

Explanation:

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$ .....(1)

For water:

Given mass of water = 35.0 g

Molar mass of water = 18 g/mol

Putting values in equation 1, we get:

$\text{Moles of water}=\frac{35.0g}{18g/mol}=1.944mol$

For ethyl alcohol:

Given mass of ethyl alcohol = 100.0 g

Molar mass of ethyl alcohol = 46 g/mol

Putting values in equation 1, we get:

$\text{Moles of ethyl alcohol}=\frac{100.0g}{46g/mol}=2.174mol$

Total moles of solution = [1.944 = 2.174] moles = 4.118 moles

Mole fraction of a substance is given by:

$\chi_A=\frac{n_A}{n_A+n_B}$

For water:

$\chi_{\text{water}}=\frac{n_{\text{water}}}{n_{\text{water}}+n_{\text{ethyl alcohol}}}$

$\chi_{water}=\frac{1.944}{4.118}=0.472$

For ethyl alcohol:

$\chi_{\text{ethyl alcohol}}=\frac{n_{\text{ethyl alcohol}}}{n_{\text{water}}+n_{\text{ethyl alcohol}}}$

$\chi_{\text{ethyl alcohol}}=\frac{2.174}{4.118}=0.528$

Dalton's law of partial pressure states that the total pressure of the system is equal to the sum of partial pressure of each component present in it.

To calculate the vapor pressure of the solution, we use the law given by Dalton, which is:

$P_T=\sum_{i=1}^n (p_i\times \chi_i)$