An atom has atomic number 20, in which group and in what period is this atom located?

A 62.6-gram piece of heated limestone is placed into 75.0 grams of water at 23.1°C. The limestone and the water come to a final

alekssr [168]

Answer:

208.7°C was the initial temperature of the limestone.

Explanation:

Heat lost by limestone will be equal to heat gained by the water

$-Q_1=Q_2$

Mass of limestone = $m_1=62.6 g$

Specific heat capacity of limestone = $c_1=0.921 J/g^oC$

Initial temperature of the limestone = $T_1=?$

Final temperature = $T_2$ =T = 51.9°C

$Q_1=m_1c_1\times (T-T_1)$

Mass of water= $m_2=75.0 g$

Specific heat capacity of water= $c_2=4.186 J/g^oC$

Initial temperature of the water = $T_3=23.1^oC$

Final temperature of water = $T_2$ =T = 51.9°C

$Q_2=m_2c_2\times (T-T_3)$

$-Q_1=Q_2$

$-(m_1c_1\times (T-T_1))=m_2c_2\times (T-T_3)$

On substituting all values:

$-(62.6 g\times 0.921 J/g^oC\times (51.9^oC-T_1))=75.0 g\times 4.186 J/g^oC\times (51.9^oC-23.1^oC)$

$T_1=208.7^oC$

208.7°C was the initial temperature of the limestone.

7 0

3 years ago

Identify the Lewis acid and Lewis base in each reaction:Na⁺ + 6H₂O ⇆ Na (H₂O)⁺₆

klemol [59]

In the reaction, Na⁺ + 6H₂O ⇆ Na (H₂O)⁺₆, Na⁺ is a Lewis acid and H₂O is a Lewis base.

<h3>What is a Lewis acid-base reaction?</h3>

According to the Lewis theory of acid-base reactions, acids accept pairs of electrons and bases donate pairs of electrons.
Any substance like H+ ion, which is capable of accepting a pair of nonbonding electrons or an electron-pair acceptor is known as a Lewis acid.
Any substance, like the OH- ion, that is capable of donating a pair of nonbonding electrons or an electron-pair donor is a Lewis base.
Here Na⁺ that is electron deficient accepts electrons from the electron donor, H₂O
From the Lewis theory, with no change in the oxidation numbers of any atoms, acids react with bases to share a pair of electrons.

To learn more about Lewis acid-base reactions: brainly.com/question/14861040

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4 0

2 years ago

WHAT ARE SOME FUN ALCHSELTER EXPERIMENTS?

Vesna [10]

You can put an egg in Vinegar an egg in Olive oil

4 0

3 years ago

hydrogen decomposes quickly when exposed to light. the reaction for decomposing hydrogen peroxide is:

Svet_ta [14]

The decomposition reaction for hydrogen peroxide is given below:

2 $H_{2}$ $O_{2}$ → 2 $H_{2}$ O + $O_{2}$

This is a decomposition reaction.

Reactions in which a reactant breaks into two or more products are known as Decomposition reactions.

AB → A + B

here, AB represents the reactant that begins the reaction, and A and B represent the products of the reaction

The decomposition reaction of decomposing hydrogen peroxide is exothermic. When the hydrogen peroxide undergoes a decomposition reaction, heat is also released along with water and oxygen.

Hence the reaction for decomposing hydrogen peroxide is :

2 $H_{2}$ $O_{2}$ → 2 $H_{2}$ O + $O_{2}$

If you need to learn more about Decomposition reaction, click here

brainly.com/question/16987748?

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5 0

1 year ago

Draw structures from the following names, and determine which compounds are optically active:(c) 1,2-dibromo-2-methylbutane

dolphi86 [110]

The given compound 1,2-dibromo-2-methylbutane is an optically active compound .

Because this compound does not have plane of symmetry (POS) and center of symmetry (COS) i.e. does not have di-symmetry . And also forms non superimposable mirror image . the compound is optically active .

It has chiral center.

Here , the chiral carbon is attached to the 4 distinct groups such as : methyl , ethyl , bromine , bromomethane .

<h3>What is di-symmetry?</h3>

Di-symmetry is that which have no center of symmetry and plane of symmetry and alternate axis of symmetry .

<h3>Chiral center :</h3>

Have Sp3 hybridized center (4sigma bond ) .

4 distinct group is attached to the chiral atom. form non -superimposable mirror image .

<h3>What is optical isomerism ?</h3>

Same molecular formula and same structural formula . also have same physical and chemical properties .

They differ in their behavior towards plane polarized light (ppl) .

Learn more about chiral center here:

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8 0

1 year ago