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3 years ago

How many moles of koh are contained in 250 ml of a 2.0 m solution of koh

1 answer:

4 0

.5 mols
Assuming that your 2.0 m is an M for molarity
I used the formula M=number of mold/L
Converted 250mL to .250L by dividing by 1000

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Consider an enzymatic reaction in which the initial concentration of substrate is low. If the amount of enzyme is held constant,

Tanzania [10]

Answer:69.8

Explanation:

3 0

1 year ago

5.00 g of a certain Compound X, known to be made of carbon, hydrogen and perhaps oxygen, and to have a molecular molar mass of 7

slega [8]

Answer:

The molecular formula = C6H6

Explanation:

Step 1: Data given

Mass of compound X = 5.00 grams

Mass of products =

CO2 = 16.39 grams

H2O = 3.46 grams

Molar mass CO2 = 44.01 g/mol

Molar mass H2O = 18.02 g/mol

Molar mass C = 12.01 g/mol

Molar mass H = 1.01 g/mol

Molar mass O = 16. 0g/mol

Step 2: Calculate moles

Moles = mass / molar mass

Moles CO2 = 16.93 grams / 44.01 g/mol

Moles CO2 = 0.385 moles

Moles C = 1* 0.385 = 0.385 moles

Moles H2O = 3.46 grams / 18.02

Moles H2O = 0.192 moles

Moles H = 2* 0.192 = 0.384 moles

Step 3: Calculate mass

Mass = moles * molar mass

Mass C = 0.385 moles *12.0 g/mol

Mass C = 4.62 grams

Mass H = 0.39 grams

Mass O = 5.00 - 4.62 -0.38 moles

Mass O = 0 grams

Step 4: Calculate mol ratio

We divide by the smallest amount of moles

C: 0.385 moles / 0.384 = 1

H: 0.384 moles / 0.384 = 1

The empirical formula is CH

This molecular formula is 13 g/mol

We have to multiply the empirical formula by n

n = 78 g/mol / 13 g/mol

n = 6

The molecular formula = 6*(CH) = C6H6

4 0

3 years ago

[50 PTS] show does the arrangement of elements on the periodic table relate to their chemical properties?

slava [35]

YES, the arrangement of elements on the periodic table relate to their chemical properties

Explanation:

As you move across a period, the atomic radius decreases due to the increase in atomic mass and hence attraction of orbitals by the increasingly positive nucleus. Therefore, the atoms become increasingly harder to lose electrons (due to increasing ionization energy) in their valence shell and more likely to take up electrons in chemical reactions.

The lower you go down the periodic table the higher the reactivity of the atoms. This is because they have more electron shells and the valence electrons are shielded from the atomic nuclei by underlying orbitals. This means that the valence electrons are easily lost (ionization energy is low) and can, therefore, react fast in chemical reactions.

Learn More:

For more on the periodic table check out;

brainly.com/question/3360897

brainly.com/question/569321

#LearnWithBrainly

4 0

3 years ago

A 51.9g sample of iron, which has a specific heat capacity of 0.449·J·g?1°C?1, is put into a calorimeter (see sketch at right) t

Ghella [55]

Answer:

the initial temperature of the iron sample is Ti = 90,36 °C

Explanation:

Assuming the calorimeter has no heat loss to the surroundings:

Q w + Q iron = 0

Also when the T stops changing means an equilibrium has been reached and therefore, in that moment, the temperature of the water is the same that the iron ( final temperature of water= final temperature of iron = T )

Assuming Q= m*c*( T- Tir)

mc*cc*(T-Tc)+mir*cir*(T - Tir) = 0

Tir = 20.3 °C + 300 g * 4.186 J/g°C * (20.3 C - 19 °C) / ( 51.9 g * 0.449 J/g°C )

Tir = 90.36 °C

Note :

- The specific heat capacity of water is assumed 1 cal/g°C = 4.186 J/g°C

- We assume no reaction between iron and water

7 0

4 years ago

What is the density at STP of the gas sulfur hexafluoride, SF6?

svetoff [14.1K]

Answer:

Explanation:

There is a formula for this:

M = DRT/P where M = molar mass. This just derived from PV = nRT where you say n = grams/molar mass. However, just with this formula, we can get D which is density at STP (1 atm and 273K). We find that D = 6.52g/L.

7 0

3 years ago

Read 2 more answers