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3 years ago

BRAINLIEST! Please help me answer the following questions:

Chemistry

1 answer:

Vlada [557]3 years ago

6 0

Explanation:

1) from the periodic table for example if u looking for K it is from the group 1A so the valancey = +1 that is mean it loses one electron to reach a stable state. and this applied for the 1A , 2A, 3A groups.

if u looking for N it is from group 5A so its valency is -3

so it gain 3 electrons to reach a stable state to complete its orbital to 8 electrons. this applied to 5A, 6A,7A

for the transition metals and simimetals other rules.

2) neutral if the element does not hold any charge like

H2, O2, N2, Fe, Au, Cu ...

isotope : if the 2 elements have same symbol and atomic number but they differ in the mass number because the have different numbers of neutrons.

if the element is charged then it is considered as an ion ex: Fe2+ then it is iron cation ( +ion)

F- then it is fluoride anion (-ion)

if u have any doubt just writ a comment ( ;

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Which of the following chemical compounds contains two hydrogen atoms in every molecule?

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Answer:

A. Water

Explanation:

H2O means that there are two hydrogen and one oxygen in every water molecule.

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How many protons are there in 20.02 mol of neon (ne)?

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In order to determine the number of protons in 20.02 mol of Ne, we use Avogadro's number to convert the number of moles to number of atoms, 1 mol = 6.022 x 10^23 atoms. From there, we must know the number of protons in a Neon atom, which is 10. Thus, the formula will be:

(20.02 mol Ne)x(6.022 x 10^23 atoms/mol)x(10 protons/1 atom Ne) =
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4 years ago

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3 years ago

A fifth-grade science class puts half of a white tablet in a test tube with 10 milliliters (mL) of water at 21°C (70°F). The tab

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3 years ago

It was calculated that 4.3mL of 0.417 M HCl is required to titrate 11.9 mL of 0.151 M Mg(OH)2. Show evidence 2 HCl(aq) + Mg(OH)2

Lapatulllka [165]

Answer:

See explanation.

Explanation:

Hello,

In this case, for the described chemical reaction:

2 HCl(aq) + Mg(OH)2(aq) → MgCl2(aq) + 2 H2O(l)

We can notice there is a 2:1 molar ratio between the moles of hydrochloric acid and magnesium hydroxide, therefore, at the equivalence point:

$n_{HCl}=2*n_{Mg(OH)_2}$

And in terms of volumes and concentrations we verify:

$V_{HCl}M_{HCl}=2*V_{Mg(OH)_2}M_{Mg(OH)_2}$

So we use the given data to proof it:

$4.3mL*0.417M=2*11.9mL*0.151M\\1.793=3.594$

Therefore, we can conclude the data is wrong by means of the 2:1 mole ratio that for sure was not taken into account. This is also supported by the fact that normalities are actually the same, but the nomality of magnesium hydroxide is the half of the hydrochloric acid normality since the acid is monoprotic and the base has two hydroxyl ions.

Best regards.

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3 years ago