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3 years ago

6

Mark’s experiment uses the reaction between baking soda and vinegar as a positive control. This is because he knows this combina

tion produces bubbling. What results would a negative control produce?

1 answer:

yarga [219]3 years ago

4 0

A negative control would be if the baking soda was expired then it might not work.

You might be interested in

Black_prince [1.1K]

Answer:

1= Magnesium

2 = Option 3 = 1s² 2s² 2p⁶

Explanation:

An electrically neutral atom consist of equal number of protons and electrons.

The answer for 1st q is magnesium because the electronic configuration showed twelve number of electrons. The atomic number of magnesium is twelve that's why this configuration is of Mg.

Mg₁₂ = 1s² 2s² 2p⁶ 3s²

The second answer is option three because has atomic number ten and third electronic configuration have ten electrons.

Ne₁₀ = 1s² 2s² 2p⁶

It is stable electronic configuration. Neon is inert because of this electronic configuration. The outer most shell is completely filled.

8 0

3 years ago

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]

<u>Answer:</u> The vapor pressure of the solution is 43.55 mmHg

<u>Explanation:</u>

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

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

<u>For water:</u>

Given mass of water = 35.0 g

Molar mass of water = 18 g/mol

Putting values in equation 1, we get:

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

<u>For ethyl alcohol:</u>

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:

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

<u>For water:</u>

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

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

<u>For ethyl alcohol:</u>

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

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

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:

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

Or,

$P_T=[(p_{\text{water}}\times \chi_{\text{water}})+(p_{\text{ethyl alcohol}}\times \chi_{\text{ethyl alcohol}}$

We are given:

Vapor pressure of water = 23.8 mmHg

Vapor pressure of ethyl alcohol = 61.2 mmHg

Putting values in above equation, we get:

$p_T=[(23.8\times 0.472)+(61.2\times 0.528)]\\\\p_T=43.55mmHg$

Hence, the vapor pressure of the solution is 43.55 mmHg

4 0

3 years ago

An ion with 11 protons 12 neutrons and a charge of + 1 has an atomic number of

posledela

Answer:

11 electrons total and 23amu

Explanation:

This tells us that sodium has 11 protons and because it is neutral it has 11 electrons. The mass number of an element tells us the number of protons AND neutrons in an atom (the two particles that have a measurable mass). Sodium has a mass number of 23amu.

5 0

3 years ago

Please help 21 points

Novosadov [1.4K]

Answer:

You

Explanation:

Will have to fill in the graph organizer with a story

4 0

3 years ago

Balanced equation for solid magnesium oxide

Y_Kistochka [10]

Answer:

Mg + O2 → MgO

Explanation:

3 0

3 years ago