Which element is a noble gas?<br> A. W<br> B. Ar<br> C. N<br> D. Er

1- Alum used in cooking is potassium aluminum sulfate hydrate, KAl(SO4)2. XH2O. To find the value of X, you can heat the sample

Burka [1]

Answer:

THE VALUE OF X IS 7 AND THE FORMULA OF THE HYDRATED SALT IS KAl(SO4)2.7H20

Explanation:

1. write out the varibales given in thequestion:

Mass of the hydrated salt = 4.74 g

Mass of water lost = 2.16 g

Formula of the hydrated salt = KAl(SO4)2. XH20

2. calculate the molar mass of the salt and that of water of crystallization:

Molar mass of anhydrous salt = ( K = 39, Al = 27, S = 32, 0=16)

= ( 39 + 27 + 32*2 + 16 * 8

= (39 + 27 + 64 + 128)

= 258 g/mol

Molar mass of water = 18 g/mol

3. Use this expression to calculate X:

The expression,

XH20 / molar mass of anhydrous salt = Mass of water lost / Mass of hydrated salt.

X = molar mass of anhydrous salt * mass of water lost / mass of anhydrous salt * H20

where XH20 is the molar mass of water of crystallization, is used to calculate the value of X.

4. Solve for X:

So therefore:

X = 258 * 2.16 / 4.74 * 18

X = 557.28/ 85.32

X = 6.53

X is approximately 7.

The value of X is 7 and the formula pf the hydrated salt is KAl(SO4)2.7H20

7 0

3 years ago

Beth’s hygrometer is reading a temperature of 30°C and a relative humidity of 65%. The humidity in the air is how many grams/cub

emmasim [6.3K]

This is asking for the absolute humidity. So if the relative humidity is 65 % and the air temperature is 30 then we need to have in mind the barometric pressure which will be 760. The humidity in the air will be 0.020 kg/m3. In order to know this we calculate it eith the mass of water vapour in a unit volume of air. This is a measure of the actual water vapour content of the air. the for mula would go like this: AH = Mv / V.

5 0

2 years ago

Colorimetric methods of analysis are based on having a reagent that changes _____________ as a function of the concentration of

GREYUIT [131]

Colorimetric methods of analysis make use of Color changes in reagents to decipher the concentration of solutions.

Therefore, color completes the sentence

<h3>Colourimetric analysis</h3>

Generally, Colorimetric analysis is used to know the concentration of a chemical element in a solution while using colour indicators or reagents.

Therefore

Colorimetric methods of analysis are based on having a reagent that changes Color as a function of the concentration of the analyte.

Color

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Consider the reaction pathway graph below.

Artemon [7]

E and Dis determine the H

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The carbon dioxide gas that was generated during this reaction was collected at 295K and 125 kPa. If 43.2 L of carbon dioxidegas

Vladimir [108]

Answer:

The balanced equation for this reaction is C2H2 + 502 + 4H2O + 3C02. What volume of carbon dioxide is produced when 2.8 L of oxygen are consumed? 25Explanation:

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Which element is a noble gas? A. W B. Ar C. N D. Er