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3 years ago

What can occur in physical change ?

1 answer:

5 0

Within a physical change, an element can change forms, such as going from solid to a liquid through melting. Color change can also occur during a physical change. Physical changes are very different from chemical changes. In a chemical change the element itself changes into something else within a reaction, such as combustion (burning).

Hope this helped

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How can heat change matter from a solid to a liquid to a gas? Help ima mark Brainlyest!!

babymother [125]

The heat energy breaks down the bonds between the molecules of the solid so the molecules become looser. Further hearing of the liquid causes the bonds to be broken down and the molecules will move further apart.

3 0

3 years ago

Read 2 more answers

A student titrates 10.00 milliliters of hydrochloric acid of unknown molarity with 1.000 m naoh. it takes 21.17 milliliters of b

Dima020 [189]

Mole ratio for the reaction is 1:1
no of moles in NaOH that reacted= 1*21.17/1000=0.02117mols
molarity of HCl=0.02117*10/1000
=2.117M

4 0

3 years ago

What chemical reactions occur in a Nelson's cell?

Cerrena [4.2K]

Explanation:

The graphite anodes are suspended into the brine. During electrolysis, Cl ions are oxidized at the anode and chlorine gas goes out of the cell, while sodium ions are reduced at the mercury cathode forming sodium amalgam. ... Hydrogen gas is obtained as a by–product at the cathode.

8 0

1 year ago

2 CuCl2 + 4 KI → 2 CuI + 4 KCl + I2

Margaret [11]

Answer: 6.75 moles

Explanation:

This is a simple stoichiometry proboe. that I would set up like this:

(13.5 moles CuCI2) (1 mol I2 / 2 moles CuCi2)

That means you all you have to do for this problem is divide by 2 and cancel out the unit moles CuCI2, which leaves you with 6.75 moles I2.

Hope this helps :)

7 0

3 years ago

Calculate the molality of a solution that contains 51.2 g of naphthalene, C10H8, in 500 mL of carbon tetrachloride. The density

PtichkaEL [24]

Answer: The molality of naphthalene solution is 0.499 m

Explanation:

Density is defined as the ratio of mass and volume of a substance.

$\text{Density}=\frac{\text{Mass}}{\text{Volume}}$ ......(1)

Given values:

Volume of carbon tetrachloride = 500 mL

Density of carbon tetrachloride = 1.60 g/mL

Putting values in equation 1, we get:

$\text{Mass of carbon tetrachloride}=(1.60g/mL\times 500mL)=800g$

Molality is defined as the amount of solute expressed in the number of moles present per kilogram of solvent. The units of molarity are mol/kg. The formula used to calculate molarity:

$\text{Molality of solution}=\frac{\text{Given mass of solute}\times 1000}{\text{Molar mass of solute}\times \text{Mass of solvent (in g)}}$ .....(2)

Given values:

Given mass of naphthalene = 51.2 g

Molar mass of naphthalene = 128.17 g/mol

Mass of solvent = 800 g

Putting values in equation 2, we get:

$\text{Molality of naphthalene}=\frac{51.2\times 1000}{128.17\times 800}\\\\\text{Molality of naphthalene}=0.499m$

Hence, the molality of naphthalene solution is 0.499 m

4 0

2 years ago