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3 years ago

11

An atom has a mass number of 55. Its number of neutrons is the sum of its atomic number and five. How many protons, neutrons, an

d electrons does this atom have? What is the identity of this atom?

1 answer:

Mariana [72]3 years ago

4 0

Answer:

Neutron number is 30

Proton number is 25

Electron number is 25

Explanation:

You might be interested in

All physical changes can be identified at the macroscopic level. true or false

Aliun [14]

Answer:

True

Explanation:

The physical changes are reversible in most cases and these changes are not the chemical changes which means that it is only the change in its state not in their nature. Just take the example of water, on cooling it becomes solid and change in color can be seen which is white in solid form and colorless in liquid form. This is also reversible and is a physical change. This means that physical changes can be identified at macroscopic level. Hence the answer is true.

5 0

3 years ago

11.9 g Cl2 is reacted with 10.7 g NaOH. How many moles of NaCl are produced?

melisa1 [442]

Answer:

1. 7.256g of NaCl

2. 47.33g of Cl2

Explanation:

2 moles of Na reacts to produce 2 moles of NaCl

8 moles of Na will still produce 8 moles of NaCl

Mass of NaCl = molar mass of Nacl/moles of Nacl

=58.5/8

=7.256g of NaCl

From the equation, 2 moles of Na reacts with 1 mole of Cl2

3/2 moles of Cl2 will react with 3 moles of Na

Mass of Cl2 = 71/1.5

=47.33g of Cl2

Explanation:

4 0

3 years ago

How many grams of magnesium chloride can be produced from 2.30 moles of chlorine gas reacting w excess magnesium Mg(s)+Cl2(g)-&g

alexdok [17]

Answer:

<em>219 g</em>

Explanation:

6 0

3 years ago

Write the balanced chemical equation between H2SO4 and KOH in aqueous solution. This is called a neutralization reaction and wil

emmainna [20.7K]

Answer:

0.166M

Explanation:

In a neutralization, the acid, H₂SO₄, reacts with a base, KOH, to produce a salt, K₂SO₄ and water. The reaction is:

H₂SO₄ + 2KOH → K₂SO₄ + 2H₂O

To solve this problem, we need to determine moles of H2SO4 and moles of KOH that reacts to find the moles of sulfuric acid that remains after the reaction:

<em>Moles H2SO4:</em>

0.650L * (0.430mol /L) = 0.2795moles H2SO4

<em>Moles KOH:</em>

0.600L * (0.240mol / L) = 0.144 moles KOH

Moles of sulfuric acid that reacts with 0.144 moles of KOH are:

0.144 moles KOH * (1mol H2SO4 / 2 mol KOH) = 0.072 moles of H2SO4 react.

And remain:

0.2795moles H2SO4 - 0.072moles H2SO4 = 0.2075 moles of H2SO4 reamains.

In 0.650L + 0.600L = 1.25L:

Molar concentration of sulfuric acid:

0.2075 moles of H2SO4 / 1.25L =

<h3>0.166M</h3>

7 0

3 years ago

The pressure of a sample of helium is 1.556 atm in a 268.5 mL container. If the container is compressed to 112.4 mL without chan

Rainbow [258]

Answer:

a. 3.72 [atm]

Explanation:

For a gas at constant temperature, (with no change in number of molecules of the gas), we can apply Boyle's Law: $P_1V_1=P_2V_2$

$(1.556[atm])(268.5[mL])=P_2(112.4[mL])$

$\dfrac{(1.556[atm])(268.5[mL\!\!\!\!\!\!\!\!{--}])}{112.4[mL \!\!\!\!\!\!\!\!{--}]}=\dfrac{P_2(112.4[mL]\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!{-----})}{112.4[mL]\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!{-----}}$

$3.716957[atm]=P_2$

It seems like the answer should have 4 significant figures since all of the other quantities have 4 significant figures, but the closest answer choice of those provided is a. 3.72

3 0

2 years ago