1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
riadik2000 [5.3K]
3 years ago
9

List 3 examples of physical change and 3 examples of chemical change.?

Chemistry
1 answer:
Sav [38]3 years ago
3 0
Examples of chemical change : 1.food scraps 2. gasoline 3. rust. 
examples of physical change : 1. juice box. 2. water. 3. rubbing alcohol.<span />
You might be interested in
If the ionization constant of water, kw, at 40°c is 2.92 × 10-14, then what is the hydronium ion concentration and ph for an aci
charle [14.2K]

Answer is: the hydronium ion concentratio is 1.71×10⁻⁷ mol/dm³ and pH<6.76.

The Kw (the ionization constant of water) at 40°C is 2.94×10⁻¹⁴ mol²/dm⁶ or 2.94×10⁻¹⁴ M².

Kw = [H₃O⁺] · [OH⁻].

[H₃O⁺] = [OH⁻] = x.

Kw = x².

x = √Kw.

x = √2.94×10⁻¹⁴ M².

x = [H₃O⁺] = 1.71×10⁻⁷ M; concentration of hydronium ion.

pH = -log[H₃O⁺].

pH = -log(1.71×10⁻⁷ M).

pH = 6.76.

pH (potential of hydrogen) is a numeric scale used to specify the acidity or basicity an aqueous solution.

5 0
3 years ago
Read 2 more answers
A chemist performs the following reaction to make sodium nitrate
vagabundo [1.1K]

Answer:

See below

Explanation:

A chemist preforms the following: Neutralizing nitric acid (HNO3) with soda ash (Na2CO3). This reaction will then create sodium nitrate and carbonic acid, which will then decompose into water (H20)

5 0
3 years ago
Read 2 more answers
Equal moles of H2, N2, O2, and He are placed into separate containers at the same temperature. Assuming each gas behaves ideally
lbvjy [14]

Answer:

They would all exhibit the same pressure.

Explanation:

Since the same number of mole of each gas is placed in different containers, it means the gas will occupy the same volume.

Now, the gases were observed at the same temperature. This means they will all have the same pressure as their volume is the same.

Now we can further understand this by doing a simple calculation as follow:

Assumptions:

For H2:

Number of mole (n) = 1 mole

Volume (V) = 22.4L

Temperature (T) = 298K

Gas constant (R) = 0.0821 atm.L/Kmol

Pressure =..?

PV = nRT

Divide both side V

P = nRT /V

P = 1 x 0.0821 x 298 / 22.4

P = 1 atm

Therefore, H2 has a pressure of 1 atm.

For N2:

Number of mole (n) = 1 mole

Volume (V) = 22.4L

Temperature (T) = 298K

Gas constant (R) = 0.0821 atm.L/Kmol

Pressure =..?

PV = nRT

Divide both side V

P = nRT /V

P = 1 x 0.0821 x 298 / 22.4

P = 1 atm

Therefore, N2 has a pressure of 1 atm

For O2:

Number of mole (n) = 1 mole

Volume (V) = 22.4L

Temperature (T) = 298K

Gas constant (R) = 0.0821 atm.L/Kmol

Pressure =..?

PV = nRT

Divide both side V

P = nRT /V

P = 1 x 0.0821 x 298 / 22.4

P = 1 atm

Therefore, O2 has a pressure of 1 atm

For He:

Number of mole (n) = 1 mole

Volume (V) = 22.4L

Temperature (T) = 298K

Gas constant (R) = 0.0821 atm.L/Kmol

Pressure =..?

PV = nRT

Divide both side V

P = nRT /V

P = 1 x 0.0821 x 298 / 22.4

P = 1 atm

Therefore, He has a pressure of 1 atm.

From the above illustrations we can see that the gases have the same pressure since they have the same number of mole, volume and were observed at the same temperature.

4 0
3 years ago
A major component of gasoline is octane (C8H18). When octane is burned in air, it chemically reacts with oxygen gas (O2) to prod
Olin [163]

Answer:

The answer is 6.25g.

Explanation:

First create your balanced equation. This will give you the stoich ratios needed to answer the question:

2C8H18 + 25O2 → 16CO2 + 18H2O

Remember, we need to work in terms of NUMBERS, but the question gives us MASS. Therefore the next step is to convert the mass of O2 into moles of O2 by dividing by the molar mass:

7.72 g / 16 g/mol = 0.482 mol

Now we can use the stoich ratio from the equation to determine how many moles of H2O are produced:

x mol H2O / 0.482 mol O2 = 18 H2O / 25 O2

x = 0.347 mol H2O

The question wants the mass of water, so convert moles back into mass by multiplying by the molar mass of water:

0.347 mol x 18 g/mol = 6.25g

8 0
3 years ago
Read 2 more answers
What is protein denaturation​
Schach [20]

Answer:

Denaturation is a process in which proteins or nucleic acids lose the quaternary structure, tertiary structure, and secondary structure which is present in their native state, by application of some

Explanation:

6 0
2 years ago
Other questions:
  • Which of the following represents positron emission? Select one: a. 3015P ---&gt; 3014Si + ___ b. 23892U ---&gt; 23490Th + ___ c
    7·1 answer
  • Using the following thermochemical data, what is the change in enthalpy for the following reaction: 3H2(g) + 2C(s) + ½O2(g) C2H5
    7·1 answer
  • Question 1 (True/False Worth 4 points) (03.06 LC) An instantaneous dipole occurs when a molecule's moving electrons are briefly
    10·2 answers
  • 1.The splitting of a heavy, unstable nucleus into two lighter nuclei is called _____.
    9·1 answer
  • An atom of 24/11 na decays by gamma decay which atom is left after the decay
    10·1 answer
  • Some molecules in air contain .<br> Explain how atoms from the air can become part of human cells
    9·1 answer
  • Which of the following increases the concentration of OH- ions?
    8·2 answers
  • ((Write any one principle of Permaculture.​
    14·1 answer
  • As the temperature increases, the molecular motion of the molecules decreases and it
    11·2 answers
  • what volume will it occupied 40 degrees celsius a gas sample was collected when a temperature is 27 degrees celsius and the volu
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!