Hydrofluoric acid (HF) can be prepared according to the following equation:

Chemistry

2 answers:

White raven [17]3 years ago

7 0

Answer:

The Hf is 34.78

Explanation:

first put it to moles with the grams times 1mol/ the atomic mass of the element or compound

Artemon [7]3 years ago

3 0

Given the balanced equation:

( Reaction type : double replacement)

CaF2 + H2SO4 → CaSO4 + 2HFI

We can determine the number of grams prepared from the quantity of 75.0 H2SO4, and 63.0g of CaF2 by converting these grams to moles per substance.

This can be done by evaluating the atomic mass of each element of the substance, and totaling it to find the molecular mass.

For H2SO4 or hydrogen sulfate it's molecular mass is the sum of the quantity of atomic mass per element. H×2 + S×1 + O×4 = ≈1.01×2 + ≈32.06×1 + ≈16×4 = 2.02 + 32.06 + 64 = 98.08 u (Dalton's or Da) or g / mol.

For CaF2 or calcium fluoride, it's molecular mass adds 1 atomic mass of calcium and 2 atomic masses of fluoride due to the number of atoms.

Ca×1 + F×2 = ≈40.07×1 + ≈19×2 = 40.08 + 38 = 78.07 u (Da or Dalton's) or g / mol.

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Calculate the number of chlorine atoms that are present in 66.05 g of dichloromethane, ch2cl2. when you have the number, take it

Whitepunk [10]

From the periodic table:
mass of carbon = 12 grams
mass of hydrogen = 1 gram
mass of chlorine = 35.5 grams
Therefore,
molar mass of CH2Cl2 = 12 + 2(1) + 2(35.5) = 85 grams

number of moles = mass / molar mass
number of moles of CH2Cl2 = 66.05 / 85 = 0.777 moles

One mole of CH2Cl2 contains two moles of Cl and each chlorine mole has Avogadro's number of atoms in it.
Therefore,
number of chlorine atoms in 0.777 moles of CH2Cl2 can be calculated as follows:
number of atoms = 0.777 * 2 * 6.022 * 10^23 = 9.358 * 10^23 atoms

Now, we will take log base 10 for this number:
log (9.358 * 10^23) = 23.97119

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3 years ago

In your own words, describe how the energy of a pendulum is changed as it moves through one cycle of its motion. Pls help online

ruslelena [56]

In a perfect world without air resistance, the top of the swing would have the most potential energy, but the least amount of kinetic energy. As the pendulum falls down, it gains more kinetic energy as it travels faster due to gravitational acceleration but loses more potential energy as it loses height. The total amount of energy in the system (the sum of kinetic and potential energy) stays the same.

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3 years ago

What is the poportion of the two chemical elements that make up water

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Answer:

2:1

hydrogen is 2 and Oxygen is one

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3 years ago

What masses of iron(iii) oxide and aluminum must be used to produce 15.0 g iron? what is the maximum mass of aluminum oxide that

defon

1) Chemical reaction:

Fe2O3 + 2Al ---> Al2O3 + 2Fe

2) molar ratios

1 mol Fe2O3 : 2Al : 1 mol Al2O3 : 2 mol Fe

3) Convert 15.0 g of iron into moles

atomic mass Fe = 55.8 g/mol

moles = mass in grams / atomic mass = 15.0 g / 55.8 g/mol = 0.269 mol

4) Use proportions to determine the moles of Fe2O3, Al, and Al2O3

a) 1mol Fe2O3 / 2 mol Fe = x / 0.269 mol Fe

x =

=> x = 0.269 mol Fe * 1 mol Fe2O3 / 2 mol Fe = 0.134 mol Fe2O3

b) 2 mol Al / 2 mol Fe = x / 0.269 mol Fe

=> x = 0.269 mol Al

c) 2 mol Fe / 1 mol Al2O3 = 0.269 mol Fe / x

=> x = 0.269 mol Fe * 1 mol Al2O3 / 2 mol Fe

x = 0.134 mol Al2O3

5) Convert moles to grams

a) Fe2O3

molar mass Fe2O3 = 2* 55.8 g/mol + 3*16g/mol = 159.6 g/mol

mass = molar mass * number of moles

mass = 159.6 g/mol * 0.134 mol = 21.4 g

b) Al

atomic mass = 27.0 g/mol

mass = number of moles * atomic mass = 0.269 mol * 27.0 g/mol = 7.26 g

c) Al2O3

molar mass = 2 * 27.0 g/mol + 3*16.0 g/mol = 102.0g/mol

mass Al2O3 = numer of moles * molar mass = 0.134 mol * 102.0 g/mol = 13.7 g

Answers:

21.4 g Fe2O3

7.26 g Al

13.7 g Al2O3

6 0

3 years ago

The reaction 2k(s) + br2(l) → 2kbr(s) is a(n) ______________ reaction.

Zinaida [17]

An oxidation reaction

5 0

3 years ago

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