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Triss [41]
3 years ago
13

A student mixes some water at room temperature with a white powder also at room temperature. The white powder disappears into th

e water, and bubbles form. The solution warms up to 30 ℃. Is this likely a physical or a chemical change? Explain your answer.
Chemistry
1 answer:
Leya [2.2K]3 years ago
5 0
Chemical change, because the white powder heated the water and caused a thermal reaction, and possibly gas was produced due to bubbles.
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The equilibrium constant has been estimated to be 0.12 at 25 °C. If you had originally placed 0.069 mol of cyclohexane in a 2.8
scZoUnD [109]

Answer: Concentrations of cyclohexane and methylcyclopentane at equilibrium are 0.0223 M and 0.0027 M respectively

Explanation:

Moles of cyclohexane = 0.069 mole

Volume of solution = 2.8 L

Initial concentration of cyclohexane =\frac{moles}{Volume}=\frac{0.069}{2.8}=0.025M

The given balanced equilibrium reaction is,

                            cyclohexane  ⇔  methylcyclopentane

Initial conc.                 0.025 M           0

At eqm. conc.       (0.025-x)M       (x) M

The expression for equilibrium constant for this reaction will be,

K= methylcyclopentane / cyclohexane

Now put all the given values in this expression, we get :

0.12=\frac{(x)}{(0.025-x)}

By solving the term 'x', we get :

x =  0.0027

Concentration of cyclohexane at equilibrium = (0.025-x ) M = (0.025-0.0027) M = 0.0223 M

Concentration of methylcyclopentane at equilibrium = (x ) M = (0.0027) M

4 0
4 years ago
An unknown gaseous substance has a density of 1.06 g/L at 31 °C and 371 torr. If the substance has the following percent composi
Anarel [89]

Answer:

C) C4H6 - Right answer

Explanation:

Let's combine the Ideal Gases Law with density to get the molecular formula for the unknown gas.

Density = mass / volume

1.06 g /L means that 1.06 grams of compound occupy 1 liter of volume.

P . V = n . R . T

Pressure in Torr must be converted to atm

760 Torr are 1 atm

371 Torr  are __ (371 .1)/760 = 0.488 atm

0.488 atm . 1L = 1.06g/MM . 0.082 . 304K

(0.488 atm . 1L) / 0.082 . 304K = 1.06g/ MM

Mass / Molar mass = Moles → That's why the 1.06 g / MM

0.0195 mol = 1.06g / MM

1.06g/0.0195 mol = MM →  54.3 g/m

Now, let's use the composition

100 g of compound have 88.8 g of C

54.3 g of compound have ___ (54.3  . 88.8) /100 = 48 g of C

100 g of compound have 11.2 g of H

54.3 g of compound have __ (54.3  .  11.2)/100 = 6 g of H

48 g of C are included un 4 atoms

6 g of H are included in 6 atoms

4 0
3 years ago
What salt is formed by the reaction of potassium hydroxide and hydrochloric acid?
Nina [5.8K]

Potassium hydroxide (KOH) is formed when Potassium forms ionic bonds with OH-ions while Potassium Oxide (K2O) is formed when potassium forms ionic bonds with the Oxide (O2-) ions. i.e. This reaction is a neutralization reaction and occurs when an acid (HCl) reacts with a base (KOH).

3 0
4 years ago
Read 2 more answers
Question #1: Identify the type of Mutation below
borishaifa [10]

Answer:

Deletion

Explanation:

A mutation refers to a change in the DNA sequence. This means that the original sequence of bases in the DNA has been altered permanently.

There are three types of DNA mutations;  base substitutions, deletions and insertions.

In the particular case of this question, the original is TTCGATA while the copy is TTGATA. If you look closely at the two, you will notice that the C has been omitted. This is an example of  deletion.

5 0
3 years ago
What are the periodic trends of ionic radii? Check all that apply.
Troyanec [42]
Atomic radii increase when going down a group and decreases when going towards the anion periods. So A and D.
6 0
3 years ago
Read 2 more answers
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