All categories

3 years ago

List three evidences of physical and chemical change. ( If you know only one or two please write them anyways please)

1 answer:

3 0

Physical: ripping paper, braking a stick, cake batter mixing

Chemical: burning paper, spoiled milk, a penny turning green

You might be interested in

For which of the following reactions does Kc = Kp?

Julli [10]

None of the choices are right

4 0

2 years ago

If 2.03 g of oxygen react with carbon monoxide, how many grams of CO2 are formed?

mamaluj [8]

Answer:

The suitable equation for this reaction is

2CO + O₂ -----> 2CO₂

Here, we are given that we have 2 grams of O₂

From the equation, we can see that 2 * Moles of O₂ = Moles of CO₂

Moles of O₂:

2/32 = 1/16 moles

Therefore, the number of moles of CO₂ is twice the moles of O₂

Moles of CO₂ = 2 * 1/16

Moles of CO₂ formed = 1/8 moles

Mass of CO₂ formed = Molar mass of CO₂ * Moles of CO₂

Mass of CO₂ formed = 44 * 1/8

Mass of CO₂ formed = 5.5 grams

Hence, option B is correct

Kindly Mark Brainliest, Thanks!!!

8 0

3 years ago

1 mol super cooled liquid water transformed to solid ice at -10 oC under 1 atm pressure.

Arada [10]

Answer:

Explanation:

Given that:

number of moles of super cooled liquid water = 1

Melting enthalpy of ice = 6020 J/mol

Freezing point =0 °C = (0 + 273 K)= 273 K

The decrease in entropy of the system during freezing for 1 mol (i.e during transformation from liquid water to solid ice ) = - 6020 J/mol × 1 mol /273 K = -22.051 J/K

Entropy change during further cooling from 0 °C (273 K) to -10 °C (263 K)

$\Delta \ S = \int\limits^{T_2}_{T_1}\dfrac{nC_p(s)dT}{T}$

$\Delta \ S = {nC_p(s)In \dfrac{T_2}{T_1}$

$\Delta \ S = {(1*37.7)In \dfrac{263}{273}$

Δ S = -1.4 J/K

Total entropy change of the system = - 22.05 J/K - 1.4 J/K = - 23.45 J/K

Entropy change of universe = entropy change of the system+ entropy change of the surrounding

According to the second law of thermodynamics

Entropy change of universe >0

SO,

Entropy change of the system + entropy change in the surrounding > 0

Entropy change in the surrounding > - entropy change of the system

Entropy change in the surrounding > - (- 23.53 J/K)

Entropy change in the surrounding > 23.53 J/K

b) Make some comments on entropy changes from the obtained data.

From the data obtained; we will realize that the entropy of the system decreases as cooling takes place when water is be convert to ice , randomness of these molecules reduces and as cooling proceeds , hence, entropy reduces more as well and the liberated heat will go into the surrounding due to this entropy of the surrounding increasing.

4 0

3 years ago

When a certain powder is mixed into a solution of silver nitrate, a white precipitate forms. When the powder is added to a solut

atroni [7]

Answer:

Ammonium chloride

Explanation:

The powder is:- Ammonium chloride

When mixed with silver nitrate, white prescipitate of silver chloride is formed as:-

$NH_4Cl+AgNO_3\rightarrow NH_4NO_3+AgCl$