What is the difference between a physical change and a chemical change? give examples for both

Chemistry

1 answer:

Tanya [424]3 years ago

7 0

Answer:

Physical change is a temporary change. A chemical change is a permanent change.

Explanation:

A Physical change affects only physical properties i.e. shape, size, etc. Chemical change both physical and chemical properties of the substance including its composition.

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List the 3 ways carbon can enter the ocean?

prohojiy [21]

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2 years ago

How much energy is required to heat 40g of water from -7 degrees Celsius to 108 degrees Celsius (Lf= 335,000J/Kg for ice)

solniwko [45]

The energy required to heat 40g of water from -7 c to 108 c is
1541000 joules

calculation

Q(heat)= M( mass) x c(specific heat capacity) xdelta t( change in temperature)

M= 40g= 40/1000= 0.04 Kg
C= 335,000 j/kg/c
delta T ( 108 --7= 115 c)

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3 years ago

Calculate how many grams would be required to prepare 600. 0 ml of 0. 150 m of naf? molar mass of naf is 41. 9 g/mo

marta [7]

Considering the definition of molarity and molar mass, the mass of NaF required is 3.771 grams.

<h3>Definition of molarity</h3>

Molar concentration or molarity is a measure of the concentration of a solute in a solution and indicates the number of moles of solute that are dissolved in a given volume.

The molarity of a solution is calculated by dividing the moles of solute by the volume of the solution:

$molarity=\frac{number of moles}{volume}$

Molarity is expressed in units $\frac{moles}{liters}$ .

<h3>Definition of molar mass</h3>

The molar mass of substance is a property defined as its mass per unit quantity of substance, in other words, molar mass is the amount of mass that a substance contains in one mole.

<h3 /><h3>Mass of NaF required</h3>

In this case, you know:

molarity= 0.15 M= 0.15 $\frac{moles}{L}$
number of moles= ?
volume= 600 mL= 0.6 L

Replacing in the definition of molarity:

$0.15\frac{moles}{L} =\frac{number of moles}{0.6 L}$

Solving:

0.15 $\frac{moles}{L}$ × 0.6 L= number of moles

<u><em>0.09 moles= number of moles</em></u>

The molar mass of NaF is 41. 9 g/mol. So, you can apply the following rule of three: If by definition of molar mass 1 mole of the compound contains 41.9 grams, 0.09 moles of the compound contains how much mass?

$mass=\frac{0.09 molesx41.9 grams}{1 mole}$