All categories

3 years ago

One example of a physical change is

Chemistry

2 answers:

Gekata [30.6K]3 years ago

8 0

Plucking eyebrows hehe

Liono4ka [1.6K]3 years ago

6 0

You choose from any of these examples for physical changes
Crumpling a sheet of aluminum foil
Melting an ice cube
Casting silver in a mold
Breaking a bottle
Boiling water
Evaporating alcohol
Shredding paper
Sublimation of dry ice into carbon dioxide vapor

You might be interested in

The bomb that destroyed tje Murrah Federal Office Building in Oklahoma City in April 1995 was constructed from ordinary material

Leto [7]

Answer:

ΔH⁰(11.4g NH₄NO₃) = -30.59Kj (4 sig. figs. ~mass of NH₄NO₃(s) given) (exothermic)

Explanation:

3NH₄NO₃(s) + C₁₀H₂₂(l) + 14O₂(g) => 3N₂(g) + 17H₂O(g) + 10CO₂(g)

ΔH⁰(f): 3(-365.6)Kj 1(-301)Kj 14(0)Kj 3(0)Kj 17(-241.8)Kj 10(-393.5)Kj

= -1096.8Kj = -301Kj = 0Kj = 0Kj = -4110.6Kj = -3930.5Kj

ΔHₙ°(rxn) = ∑ (ΔH˚(f)products) - ∑(ΔH˚(f)reactants)

= [3(0)Kj + 17(-241.8)Kj + (-393.5)Kj] - [(-(1096.8)Kj + (-301)Kj + (0)Kj]

= [-(8041.1) - (-1397.8)]Kj

= -6643.3Kj (for 3 moles NH₄NO₃ used in above equation)

∴ Standard Heat of Rxn = -6643.3Kj/3moles = -214.8Kj/mole NH₄NO₃(s)

ΔH°(rxn for 14.11g NH₄NO₃(s)) = (11.4g/80.04g·mol⁻¹)(-214.8Kj/mol) = 30.5937Kj ≅ 30.59Kj (4 sig. figs. ~mass of NH₄NO₃(s) given)

5 0

3 years ago

A pea plant has two dominant alleles for plant height – tall. We say that this plant is?:

Irina-Kira [14]

I think the answer is codominant??

3 0

3 years ago

What is the classification of a solution of naoh with a ph of 8.3?

Maksim231197 [3]

Answer:

<u>Alkaline or basic solution </u>(alkaline and basic means the same)

Explanation:

According to the <em>pH</em>, solutions may be classified as neutral, acidic, or alkaline (basic).

This table shows such classification:

pH classification

7 neutral

> 7 alkaline or basic

< 7 acidic

Thus, since the pH of the solution is 8.3, which is greater than 7, the solution is classified as basic (alkaline).

Additionally, you must learn that pH is a logarithmic scale for the concentration of hydronium ions in the solution.

pH = - log [H₃O⁺]

You can calculate the concentration of hydronium ions using antilogarithm properties:

$pH=-log[H_3O^+]\\ \\ {[H_3O^+]}=10^{-pH}\\ \\ {[H_3O^+]}=10^{-8.3}=0.00000000501$

NaOH solutions are alkaline solutions, bases, according to Arrhenius model, because they contain OH⁻ ions and release them when ionize in water.

8 0

3 years ago

Exercise 2:

vagabundo [1.1K]

Answer:

1. KCLO3------>KCL + 3/2O2(g)

2. 122.5g/mol

3. 0.2mol

4. 18.5g

7 0

3 years ago

Which chemical is responsible for opening the hair cuticle?

SashulF [63]

Peroxide is the chemical responsible for opening the hair cuticle

6 0

3 years ago