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3 years ago

Help its rlly hard pls

Chemistry

2 answers:

Ostrovityanka [42]3 years ago

7 0

Answer:

Choice 1. Volume

Explanation:

Volume is a way of measuring the amount of space filled inside a 3-dimensional object. Temperature would not be correct because that is the measure of kinetic energy and particles moving. Mass is incorrect because that measures the weight, not the amount of space filled. Density is mass per volume which would also be incorrect.

Blizzard [7]3 years ago

3 0

Answer:

Volume

Explanation:

Volume is the amount of space taken up or occupied by an object.

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What would be the colour of litmus in sodium carbonate?<br> will make brainliest

gregori [183]

Answer:

the color of the litmus paper will turn into blue color because sodium carbonate is basic in nature

7 0

3 years ago

A hot lump of 30.5 g of iron at an initial temperature of 52.7 °C is placed in 50.0 mL H2O initially at 25.0 °C and allowed to r

slava [35]

Answer:

26.7°C

Explanation:

Using the formula; Q = m × c × ΔT

Where; Q = amount of heat

m = mass

c = specific heat

ΔT = change in temperature

In this question involving iron placed into water, the Qwater = Qiron

For water; m= 50g, c = 4.18 J/g°C, Initial temp= 25°C, final temp=?

For iron; m = 30.5g, c = 0.449J/g°C, Initial temp= 52.7°C, final temp=?

Qwater = -(Qiron)

m × c × ΔT (water) =- {m × c × ΔT (iron)}

50 × 4.18 × (T - 25) = - {30.5 × 0.449 × (T - 52.7)}

209 (T - 25) = - {13.6945 (T - 52.7)}

209T - 5225 = -13.6945T + 721.7

209T + 13.6945T = 5225 + 721.7

222.6945T = 5946.7

T = 5946.7/222.6945

T = 26.7

Hence, the final temperature of water and iron is 26.7°C

8 0

3 years ago

3.5g of a Certain compound X, known to be made of carbon, hydrogen, and perhaps oxygen, and to have a molecular molar mass of 15

shutvik [7]

Answer:

C₅H₁₀O₅

Explanation:

1. Calculate the mass of each element in 2.78 mg of X.

(a) Mass of C

$\text{Mass of C} = \text{5.13 g CO}_{2}\times \dfrac{\text{12.01 g C}}{\text{44.01 g }\text{CO}_{2}}= \text{1.400 g C}$

(b) Mass of H

$\text{Mass of H} = \text{2.10 g H$_{2}$O}\times \dfrac{\text{2.016 g H}}{\text{18.02 g H$_{2}$O}} = \text{0.2349 g H}$

(c) Mass of O

Mass of O = 3.5 - 1.400 - 0.2349 = 1.87 g

2. Calculate the moles of each element

$\text{Moles of C = 1400 mg C}\times\dfrac{\text{1 mmol C}}{\text{12.01 mg C }} = \text{116.6 mmol C}\\\\\text{Moles of H = 234.9 mg H} \times \dfrac{\text{1 mmol H}}{\text{1.008 mg H}} = \text{233.1 mmol H}\\\\\text{Moles of O = 1870 mg O} \times \dfrac{\text{1 mmol O}}{\text{16.00 mg O}} = \text{116 mmol O}$

3. Calculate the molar ratios

Divide all moles by the smallest number of moles.

$\text{C: } \dfrac{116.6}{116.6}= 1\\\\\text{H: } \dfrac{233.1}{116.6} = 1.999\\\\\text{O: } \dfrac{116}{116.6} = 1.00$

4. Round the ratios to the nearest integer

C:H:O = 1:2:1

5. Write the empirical formula

The empirical formula is CH₂O.

6. Calculate the molecular formula.

EF Mass = (12.01 + 2.016 + 16.00) u = 30.03 u

The molecular formula is an integral multiple of the empirical formula.

MF = (EF)ₙ

$n = \dfrac{\text{MF Mass}}{\text{EF Mass }} = \dfrac{\text{150 u}}{\text{30.03 u}} = 5.00 \approx 5$

MF = (CH₂O)₅ = C₅H₁₀O₅

The molecular formula of X is C₅H₁₀O₅.

8 0

3 years ago

The pipet used for transferring the pickle juice to the flask was dirty and consequentially some of the pickle juice stuck to th

lesya [120]

Explanation:

Since, some of the given sample is stuck inside and behind the pipet. Hence, there will occur a decrease in the percent of acetic acid.

This is because a decrease in concentration of the acid will also lead to a decrease in the amount of sample taken for the estimation. Since. lesser is the amount or concentration present lesser will be its analyte concentration.

For example, we took 10 mg of a pickel sample but 3 mg of the sample remain stuck in the pipet. This means we actually titrating a sample less than 10 mg.

Therefore, the analyte concentration in the pickel will also be less.

6 0

3 years ago

The atomic mass is the sum of the number of ________ and ________ in the nucleus of an atom. Choose two answers from the options

iVinArrow [24]

Answer :

The atomic mass is the sum of the number of protons and neutrons in the nucleus of an atom.

Explanation :

Atomic number : it is defined as the number of protons or number of electrons.

Atomic number = number of protons = number of electrons

Mass number or atomic mass : It is defined as the sum of the number of protons and the number of neutrons.

Mass number or atomic mass = Number of protons + Number of neutrons

For example :

Number of protons in carbon = 6

Number of neutrons in carbon = 6

Mass number or atomic mass = Number of protons + Number of neutrons

Mass number or atomic mass = 6 + 6

Mass number or atomic mass = 12

Thus, the atomic mass is the sum of the number of protons and neutrons in the nucleus of an atom.

3 0

3 years ago

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