All categories

3 years ago

22 points!

Chemistry

1 answer:

olya-2409 [2.1K]3 years ago

4 0

Answer:

The second picture is the representation of chemical change.

Explanation:

The first picture shows the physical change because in this case heat is supplied to the molecules and they move away from each others without changing the composition. It is just like the transformation of liquid water into gas. when the water is heated it evaporated without changing the composition. While the second image shows the chemical change because two substance are combined and form a new substance. Which is different from the reactants.

Chemical:

The changes, that occur due to change in the composition of a substance and result in a different compound is known as chemical change.

These changes are irreversible

These changes occur due to chemical reactions

Example:

Combustion of fuel or wood: that oil or wood convert into energy, CO2 and ash in case of wood

Boiling of egg: that change the chemical composition of protein in the egg

Physical Change

The changes that occur only due to change in shape or form but their chemical or internal composition remain unchanged.

These changes were reversible.

They have same chemical property.

Example

Water converting to Ice

Water converting to gas

In this water molecule remain the same only they rearrange themselves that change its state of mater not composition

You might be interested in

What volume (in mL) of a 0.200 MHNO3 solution is required to completely react with 27.6 mL of a 0.100 MNa2CO3 solution according

ladessa [460]

Answer:

There is 27.6 mL of a 0.200 M HNO3 solution required

Explanation:

Step 1: The balanced equation is:

Na2CO3(aq)+2HNO3(aq)→2NaNO3(aq)+CO2(g)+H2O(l)

This means for 1 mole Na2CO3 consumed, there is consumed 2 mole of HNO3 and there is produced 2 moles of NaNO3, 1 mole of CO2 and 1 mole of H2O

Step 2: Calculating moles of Na2CO3

moles of Na2CO3 =volume of Na2CO3 * Molarity of Na2CO3

moles of Na2CO3 = 27.6 *10^-3 * 0.1 M = 0.00276 moles

Step 3: Calculating moles of HNO3

In the balanced equation, we can see that for 1 mole of Na2CO3 consumed, there are consumed 2 moles of HNO3.

So for 0.00276 moles consumed of Na2CO3, there are consumed 0.00552 moles of HNO3.

This means 0.00276 moles of the base Na2CO3 would react with 0.00552 moles of the acid HNO3

Step 4: Calculating the volume of HNO3

volume of HNO3 = moles of HNO3 / Molarity of HNO3

volume of HNO3 = 0.00552 moles / 0.200 M = 0.0276 L

0.0276 L = 27.6 ml

There is 27.6 mL of a 0.200 M HNO3 solution required

4 0

3 years ago

The average distance between nitrogen and oxygen atoms is 115 pm in a compound called nitric oxide. what is this distance in cen

e-lub [12.9K]

pm stands for picometer and picometers are units which can be used to measure really tiny distances. One picometer is equal to 10^{-12} meters. We know that one centimeter is equal to 10^{-2} m so there are 10^2 cm per meter. We can change the distance d = 115 pm to units of centimeters. d = (115 pm) x (10^{-12}m / pm) x (10^2 cm / m) d = 115 x 10^{-10} cm = 1.15 x 10^{-8} cm The distance in centimeters is 1.15 x 10^{-8} cm

7 0

3 years ago

Balance the following chemical equations

jok3333 [9.3K]

Answer:

2N2 + O2 ⇒ 2N2O

Explanation:

Since I cannot see the product's of the second chemical equation I will only solve the first one.

In order to balance a chemical equation you need to make sure that the atoms on both sides are equal.

In this case we have...

N2 + O2 = N2O

N = 2

O = 2

N = 2

O = 2

Change the coefficient:

N2O = 2N20

2 × 2 = 4

1 × 2 = 2

2N2 + O2 ⇒ 2N2O

Hope this helps.

4 0

3 years ago

Calculate the oxidation number of “C” in CH3COCH3 please

Triss [41]

Answer:

The oxidation number of C (carbon) is +4

Explanation:

8 0

4 years ago

4. Balance the following chemical equation. Say what the coefficients "a"

lisabon 2012 [21]

Answer:

a = 4

b = 3

Explanation:

SOLUTION :-

Balance it by using 'hit & trial' method , and you'll get the answer :-

2Fe₂O + 3C → 4Fe + 3CO₂

⇒ a = 4 ; b = 3

VERIFICATION :-

In reactant side of equation :-

Number of atoms in Fe = 2×2 = 4
Number of atoms in O = 2×3 = 6
Number of atoms in C = 3×1 = 3

In product side of equation :-

Number of atoms in Fe = 4×1 = 4
Number of atoms in C = 3×1 = 3
Number of atoms in O = 3×2 = 6

Number of atoms of each element is equal in both reactant & product side of equation. Hence , the equation is balanced.

6 0

3 years ago