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Which one of the give elements the least reactive?

nika2105 [10]

Answer:

c

Explanation:

iodine is the answer.please mark me as brianlist.

7 0

3 years ago

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1. Using the balanced equation, answer the following questions:

nalin [4]

Answer:

a) 2.53 × 10²³ molecules of O₂

b) 31.90 g of KCl

Explanation:

The balance chemical equation for given decomposition reaction is as follow;

2 KClO₃ → 2 KCl + 3 O₂

Step 1: <u>Calculate Moles for given amount of KClO₃;</u>

Moles = Mass / M.Mass

Moles = 34.35 g / 122.55 g/mol

Moles = 0.280 moles of KClO₃

Step 2: <u>Find out moles of O₂ produced;</u>

According to eq,

2 moles of KClO₃ produces = 3 moles of O₂

So,

0.280 moles of KClO₃ will produce = X moles of O₂

Solving for X,

X = 0.280 mol × 3 mol / 2 mol

X = 0.42 moles of O₂

Step 3: <u>Calculate No. of Molecules of O₂ as,</u>

No. of Molecules = Moles × 6.022 × 10²³

No. of Molecules = 0.42 mol × 6.022 × 10²³ molecules/mol

No. of Molecules = 2.53 × 10²³ molecules of O₂

Step 1: <u>Calculate Moles for given amount of KClO₃;</u>

Moles = Mass / M.Mass

Moles = 52.53 g / 122.55 g/mol

Moles = 0.428 moles of KClO₃

Step 2: <u>Find out moles of KCl produced;</u>

According to eq,

2 moles of KClO₃ produces = 2 moles of KCl

So,

0.428 moles of KClO₃ will produce = X moles of KCl

Solving for X,

X = 0.428 mol × 2 mol / 2 mol

X = 0.428 moles of KCl

Step 3: <u>Calculate Mass of KCl as;</u>

Mass = Moles × M.Mass

Mass = 0.428 mol × 74.55 g/mol

Mass = 31.90 g of KCl

6 0

3 years ago

Rank the following substances in order from most soluble in water to least soluble in water: methane, CH4; 2-butanol, C4H9OH; ma

Taya2010 [7]

Answer: The given substances are placed in order from most soluble in water to least soluble in water as follows.

$MgCl_{2}$ > $C_{4}H_{9}OH$ > $C_{3}H_{8}$ > $CH_{4}$

Explanation:

It is known that like dissolves like which means a polar compound will be soluble in a polar solvent. And, a non-polar compound will be soluble in non-polar solvent.

Ionic compounds are soluble in polar solvent like water. For example, $MgCl_{2}$ is an ionic compound and it is readily soluble in water.

2-butanol ( $C_{4}H_{9}OH$ ) is also a polar compound and it will also dissolve in water but to a lesser extent as compared to magnesium chloride.

Whereas both methane and propane are non-polar in nature. But as propane is larger in size as compared to methane so, it will be slightly more soluble in water as compared to methane.

Thus, we can conclude that the given substances are placed in order from most soluble in water to least soluble in water as follows.

$MgCl_{2}$ > $C_{4}H_{9}OH$ > $C_{3}H_{8}$ > $CH_{4}$

5 0

3 years ago

If a hydrogen atom and a helium atom have the same kinetic energy:________

Nuetrik [128]

Answer: If a hydrogen atom and a helium atom have the same kinetic energy then the wavelength of the hydrogen atom will be roughly equal to the wavelength of the helium atom.

Explanation:

The relation between energy and wavelength is as follows.

$E = \frac{hc}{\lambda}\\$

This means that energy is inversely proportional to wavelength.

As it is given that energy of a hydrogen atom and a helium atom is same.

Let us assume that $E_{hydrogen} = E_{helium} = E'$ . Hence, relation between their wavelengths will be calculated as follows.

$E_{hydrogen} = \frac{hc}{\lambda_{hydrogen}}$ ... (1)

$E_{helium} = \frac{hc}{\lambda_{helium}}$ ... (2)

Equating the equations (1) and (2) as follows.

$E_{hydrogen} = E_{helium} = E'\\\frac{hc}{\lambda_{hydrogen}} = \frac{hc}{\lambda_{helium}} = E'\\\lambda_{helium} = \lambda_{hydrogen} = E'$

Thus, we can conclude that if a hydrogen atom and a helium atom have the same kinetic energy then the wavelength of the hydrogen atom will be roughly equal to the wavelength of the helium atom.

7 0

3 years ago

Which of the following weak interactions would require the least amount of energy to disrupt? Group of answer choices

SpyIntel [72]

Answer: Option (c) is the correct answer.

Explanation:

A hydrogen bond is defined as a weak bond that is formed between an electropositive atom (generally hydrogen atom) and an electronegative atom like oxygen, nitrogen and fluorine.

An ionic bond is defined as a bond formed between a metal and a non-metal and in this bond transfer of electron takes place from metal to non-metal. And, due to the presence of opposite charges on the combining atoms there exists a strong force of attraction.

Vander waal forces are defined as the weak electric forces which tend to attract neutral molecules towards each other in gases, liquefied and solidified gases.

Vander waal forces are very weak forces.

Thus, we can conclude that Van der walas interactions are weak interactions would require the least amount of energy to disrupt.

8 0

3 years ago

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