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2 years ago

Which element gives up its valence electrons most readily? Bi Fr Be Ar

Chemistry

1 answer:

dybincka [34]2 years ago

7 0

Answer:

It's the Fr

Explanation:

Because it have only 1 valence electron and it's far from the nucleus

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A balloon inflated in a room at 24 degree celsius has a volume of 4 L. The balloon is then heated to a temperature of 58 degree

WITCHER [35]

Answer: The new volume of the balloon will be 4.45L

Explanation: We will solve this question through the concept of Charles's law. The law states that the volume of a gas is directly proportional to the absolute temperature, assuming the quantity of gas and pressure remain constant.

8 0

2 years ago

A cup of cocoa is left on the counter. Which best describes how its temperature changes? a) the heat leaves the cup of cocoa b)

zysi [14]

I'm going to have to say A. My reason to that is because when you leave a cup of hot cocoa (assuming its hot), it gives off the heat (exothermic) the

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3 years ago

How many kJ of heat are released by the reaction of 25.0 g of Na2O2(s) in the following reaction? (M = 78.0 g/mol for Na2O2)

solong [7]

-20.16 KJ of heat are released by the reaction of 25.0 g of Na2O2.

Explanation:

Given:

mass of Na2O2 = 25 grams

atomic mass of Na2O2 = 78 gram/mole

number of mole = $\frac{mass}{atomic mass of 1 mole}$

= $\frac{25}{78}$

=0. 32 moles

The balanced equation for the reaction:

2 Na2O2(s) + 2 H2O(l) → 4 NaOH(aq) + O2(g) ∆Hο = −126 kJ

It can be seen that 126 KJ of energy is released when 2 moles of Na2O2 undergoes reaction.

similarly 0.3 moles of Na2O2 on reaction would give:

$\frac{126}{2}$ = $\frac{x}{0.32}$

x = $\frac{126 x 0.32}{2}$

= -20.16 KJ

Thus, - 20.16 KJ of energy will be released.

6 0

3 years ago

If 9.85 grams of copper metal react with 31.0 grams of silver nitrate, how many grams of copper nitrate can be formed and how ma

Veseljchak [2.6K]

Answer:-

29.07 gram of Cu(NO3)2 will be formed.

4.756 grams of AgNO3 will be left over when the reaction is complete.

Explanation:-

Atomic weight of Cu = 63.546 g mol -1

Molecular weight of AgNO3 = 107.87 x 1 + 14 x 1 + 16 x 3

= 169.87 g mol-1

Number of moles of Copper = 9.85 gram / (63.546 g mol-1)

= 0.155 mol

Number of moles of AgNO3 = 31 gram / ( 169.87 g mol-1)

= 0.183 mol

The balanced chemical equation for this reaction is

Cu + AgNO3 --> Cu(NO3)2 + Ag

According to the equation,

1 mole of Cu reacts with 1 mole of AgNO3.

∴0.155 mol of Cu react with 0.155 mol of AgNO3.

Number of moles of AgNO3 left over = 0.183-0.155=0.028 mol

Number of grams of AgNO3 left over = 0.028 mol x 169.87 grams mol-1

= 4.756 gram

Molecular weight of Cu(NO3)2 = 63.546 x 1 + (14 x 1 +16 x 3 ) x 2

=187.546 gram

Now from the balanced chemical equation,

1 Cu gives 1 Cu(NO3)2

∴ 63.546 g of Cu gives 187.546 gram of Cu(NO3)2

9.85 grams pf Cu gives 187.546 x 9.85 / 64.546 gram of Cu(NO3)2

= 29.07 gram of Cu(NO3)2

4 0

3 years ago

What is included in a compaarative investigation

Minchanka [31]

a scientific question

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3 years ago