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NISA [10]
3 years ago
11

PLEASE HELP THIS IS IMPORTANT. Answer the ones u know leave the ones u don’t. Be specific too and I’ll give u a brainlist/5 star

!!!
1) you would have noticed water vapour forming on the inside of the glass jar, where did this water come from?

hint: Think about what happens in a combustion in a combustion reaction.


2) explain why the water rises in the glass jar?
Chemistry
1 answer:
LekaFEV [45]3 years ago
5 0

Answer:

1) Condensation.

2) See below.

Explanation:

1) The warmer water vapour from the surroundings came into contact with the cooler inner surface of the glass jar and condensed, forming the water droplets (water vapour) on the inside of the glass jar.

2) As condensation occurs, condensed water vapour will drip into the water solution in the glass jar, causing the water to rise in the glass jar.

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What are the two parts of a solution?
Vlad [161]
The 2 parts or components that make up a solution would be the solute and the solvent.
6 0
3 years ago
What is the reduction half-reaction for the equation below?
Katen [24]

Answer:

MnO_4^-+8H^++5e^-\rightarrow Mn^{2+}+4H_2O

Explanation:

Hello there!

In this case, since redox reactions are characterized by the presence of a reduction reaction, whereby the oxidation of the element decreases, and an oxidation reaction whereby the oxidation of the element increases.

In such a way, for the given chemical equation, we can see Fe is increasing its oxidation state from 2+ to 3+, which means it is oxidized. On the flip side, Mn is being reduced from 7+ (MnO₄⁻) to 2+ and this, the reduction half-reaction is:

MnO_4^-+8H^++5e^-\rightarrow Mn^{2+}+4H_2O

Whereas five electrons are carried.

Regards!

3 0
3 years ago
When 6.040 grams of a hydrocarbon, CxHy, were burned in a combustion analysis apparatus, 18.95 grams of CO2 and 7.759 grams of H
algol [13]

Answer: The empirical formula is CH_2 and molecular formula is C_4H_8

Explanation:

We are given:

Mass of CO_2 = 18.95 g

Mass of H_2O= 7.759 g

Molar mass of carbon dioxide = 44 g/mol

Molar mass of water = 18 g/mol

For calculating the mass of carbon:

In 44g of carbon dioxide, 12 g of carbon is contained.

So, in 18.59 g of carbon dioxide, =\frac{12}{44}\times 18.59=5.07g of carbon will be contained.

For calculating the mass of hydrogen:

In 18g of water, 2 g of hydrogen is contained.

So, in 7.759 g of water, =\frac{2}{18}\times 7.759=0.862g of hydrogen will be contained.

Mass of C = 5.07 g

Mass of H = 0.862 g

Step 1 : convert given masses into moles.

Moles of C =\frac{\text{ given mass of C}}{\text{ molar mass of C}}= \frac{5.07g}{12g/mole}=0.422moles

Moles of H=\frac{\text{ given mass of H}}{\text{ molar mass of H}}= \frac{0.862g}{1g/mole}=0.862moles

Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.

For C =\frac{0.422}{0.422}=1

For H =\frac{0.862}{0.422}=2

The ratio of C : H = 1: 2

Hence the empirical formula is CH_2.

The empirical weight of CH_2 = 1(12)+2(1)= 14 g.

The molecular weight = 56.1 g/mole

Now we have to calculate the molecular formula.

n=\frac{\text{Molecular weight }}{\text{Equivalent weight}}=\frac{56.1}{14}=4

The molecular formula will be=4\times CH_2=C_4H_8

6 0
3 years ago
A. Match each type of titration to its pH at the equivalence point.
maks197457 [2]

Answer:answers are in the explanation

Explanation:

(a). pH less than 7 between 1 - 3.5 are strong acid, and between 4.5-6.9 weak acid.

pH greater than 7; between 10-14 is a strong base, and between 7.1 - 9, it is weakly basic.

(b). Equation of reaction;

HBr + KOH ---------> KBr + H2O

One mole of HBr reacts with one mole of KOH to give one Mole of KBr and one mole of H2O

Calculating the mmol, we have;

mmol KOH = 28.0 ml × 0.50 M

mmol KOH= 14 mmol

mmol of HBr= 56 ml × 0.25M

mmol of HBr= 14 mmol

Both HBr and KOH are used up in the reaction, which leaves only the product,KBr and H2O.

The pH here is greater than 7

(C). [NH4^+] = 0.20 mol L^-1 × 50 ml. L^-1 ÷ 50 mL + 50mL

= 0.10 M

Ka=Kw/kb

10^-14/ 1.8× 10^-5

Ka= 5.56 ×10^-10

Therefore, ka= x^2 / 0.20

5.56e-10 = x^2/0.20

x= (0.20 × 5.56e-10)^2

x= 1.05 × 10^-5

pH = -log [H+]

pH= - log[1.05 × 10^-5]

pH = 4.98

Acidic(less than 7)

(c). 0.5 × 20/40

= 0.25 M

Ka= Kw/kb

kb= 10^-14/1.8× 10^-5

Kb = 5.56×10^-10

x= (5.56×10^-10 × 0.5)^2

x= 1.667×10^-5 M

pH will be basic

3 0
3 years ago
Provide a general comparison of the empty space in a solid with that in a liquid as well as
bogdanovich [222]
Assuming that the space within the solid or liquid is vacuum, it is not matter because there is no mass inside. However, there is a volume. The volume inside a solid would have regular straight sides because atoms of a solid is compactly arranged. For liquids, the space could be irregular curves and paths because the atoms in a liquid are free-flowing.
8 0
3 years ago
Read 2 more answers
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