All categories

4 years ago

How are physical and chemical changes different

Chemistry

2 answers:

Wittaler [7]4 years ago

3 0

Answer:

physic

Explanation:

physical chnages are chnages to the appearance

chemical chnages are chnages like

color temperature chnaging fromna gas to a liquid etc

mariarad [96]4 years ago

3 0

Answer:

Explanation:

Physical changes do not change the properties of the initial substance. Physical changes are temporary. For eg if you boil water, it turns into vapor. It's chemical composition is still H2O but now its just in gas form instead of liquid but overtime that gas will condensate into water. SO physical changes are reversible most of the times.

Chemical changes change the properties of initial substance. Like burning wood, you can't really reverse this reaction because you can't go from coal to wood, its permanent change. So chemical changes are permanent changes. Like souring milk, acid-base reactions, rotting banana etc.

You might be interested in

If you mix a 25.0mL sample of a 1.20m potassium sulfide solution with 15.0 mL of a 0.900m basium nitrate solution and the reacti

ddd [48]

Answer:

Limiting reagent: barium nitrate

Theoretical yield: 2.29 g BaS

Percent yield: 87%

Explanation:

The corrected balanced reaction equation is:

K₂S + Ba(NO₃)₂ ⇒ 2KNO₃ + BaS

The amount of potassium sulfide added is:

(25.0 mL)(1.20mol/L) = 30 mmol

The amount of barium nitrate added is:

(15.0mL)(0.900mol/L = 13.5 mmol

Since the reactant react in a 1:1 molar ratio, barium nitrate is the limiting reagent. If all of the limiting reagent reacts, the amount of barium sulfide produced is:

(13.5 mmol Ba(NO₃)₂)(BaS/Ba(NO₃)₂ ) = 13.5 mmol BaS

Converting this amount to grams gives the theoretical yield of BaS (molar mass 169.39 g/mol).

(13.5 mmol)(169.39 g/mol)(1g/1000mg) = 2.29 g BaS

The percent yield is calculated as follows:

(actual yield) / (theoretical yield) x 100%

(2.0 g) / (2.29 g) x 100% = 87%

6 0

3 years ago

The electron configuration of an element is 1s22s22p63s1. Describe what most likely happens when an atom of this element comes n

bearhunter [10]

Answer:

The element with electron configuration 1s² 2s² 2p⁶ will most likely not........

Explanation:

5 0

2 years ago

What must occur before clouds can form?

fomenos

Evaporation must happen before they can form, because clouds are condensing, which means that they first have to evaporate, then they will condense, and form clouds.

5 0

3 years ago

Read 2 more answers

Which statement best explains the change in the matter before and after the change?

Luda [366]

Answer: change

Explanation:

Change is change and sometimes it can be good and sometimes it can be bad.

3 0

3 years ago

(22 points) Gas conversion problems #4-7 pls I have no idea how to solve this and i’ve tried but i don’t get it :(

vova2212 [387]

Answer:

See attached

Explanation:

The empirical gas laws relate the effect of one gas-law variable upon another. The gas-law variables include Pressure (P), Volume(V), Temperature(T) and mass (n). When two of the four variables are related holding the other two constant, the relationships are called 'The Empirical Gas Laws'.

These include

Boyles Law* => P ∝ 1/V; Temp & mass remain constant => P₁·V₁ = P₂V₂

(NOTE => Boyles Law is the only 'inverse' empirical relationship)

Charles Law => V ∝ T; Press & mass remain constant => V₁/T₁ = V₂/T₂

Gay-Lussac Law => P ∝ T; Vol & mass remain constant => P₁/T₁ = P₂/T₂

Avogadro's Law => n ∝ V; Press & Temp remain constant => n₁/V₁ = n₂/V₂

Combined Law => All variables in play => P₁V₁/n₁T₁ = P₂V₂/n₂T₂

*Note => <u>Convert all Temperature values to Kelvin</u> when working with Empirical Gas Laws. If a different dimension is needed, convert after working with Kelvin values. => ( K = °C + 273 )

__________________

Standards of the Gas Laws at 0°C(273K) STP

(Std Intn'l System) Other common equivalent unit values

Pressure 1 Atm 760mmHg, 101.325Kpa, 760 Torr, 14.2 lbs/in²

Volume 1 Liter

mass 1 mole

Temperature 0°C(=273K) K = °C + 273

___________________

4. ?Atm = 758.7mmHg

758.8mmHg = 758.7mmHg x (1Atm/760mmHg) = 0.9983 Atm

5. ?Kpa = 760.00mmHg x (1 Atm/760.00mmHg) x 101.325Kpa/1Atm)

= 101.325Kpa

6. Boyles Law => Decrease Pressure => Increase Volume (of gas) in bag.

P₁ = 101.325Kpa => P₂ = 99.82Kpa

P₁V₁ = P₂V₂ => V₂ = P₁V₁/P₂ = V₁(101.325Kpa/99.82Kpa) = 1.015·V₁ => That is, the volume of gas in bag will expand to 1.015 x that at sea level. The bag may burst if not elastic.

7. ?Kpa = 2.56Atm

2.56Atm = 2.56Atm x 101.325Kpa/1Atm = 259.392Kpa

6 0

3 years ago