1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
lianna [129]
3 years ago
10

How many molecules are in 145.5 grams of Be(OH)2

Chemistry
1 answer:
Zanzabum3 years ago
3 0

Answer:

2.04 x 10²⁴ molecules

Explanation:

Given parameters:

Mass of Be(OH)₂ = 145.5g

To calculate the number of molecules in this mass of Be(OH)₂ we follow the following steps:

>> Calculate the number of moles first using the formula below:

Number of moles = mass/molarmass

Since we have been given the mass, let us derive the molar mass of Be(OH)₂

Atomic mass of Be = 9g

O = 16g

H = 1g

Molar Mass = 9 + 2(16 + 1)

= 9 + 34

= 43g/mol

Number of moles = 145.5/43 = 3.38mol

>>> We know that a mole is the amount of substance that contains Avogadro’s number of particles. The particles can be atoms, molecules, particles etc. Therefore we use the expression below to determine the number of molecules in 3.38mol of Be(OH)₂:

Number of

molecules= number of moles x 6.02 x 10²³

Number of molecules= 3.38 x 6.02 x 10²³

= 20.37 x 10²³ molecules

= 2.04 x 10²⁴ molecules

You might be interested in
The question is in the picture below
Rus_ich [418]

Answer:

\Delta\text{H}_1+2\Delta\text{H}_2-\Delta\text{H}_3

Explanation:

Hess's Law of Constant Heat Summation states that if a chemical equation can be written as the sum of several other chemical equations, the enthalpy change of the first chemical equation is equal to the sum of the enthalpy changes of the other chemical equations. Thus, the reaction that involves the conversion of reactant A to B, for example, has the same enthalpy change even if you convert A to C, before converting it to B. Regardless of how many steps it takes for the reactant to be converted to the product, the enthalpy change of the overall reaction is constant.

With Hess's Law in mind, let's see how A can be converted to 2C +E.

\bf{\text{A} \rightarrow 2\text{B}}                  (Δ\text{H}_1)  -----(1)

Since we have 2B, multiply the whole of II. by 2:

\bf{2\text{B} \rightarrow 2\text{C} +2\text{D}}       (2Δ\text{H}_2) -----(2)

This step converts all the B intermediates to 2C +2D. This means that the overall reaction at this stage is \text{A} \rightarrow 2\text{C} +2\text{D}.

Reversing III. gives us a negative enthalpy change as such:

\bf{2\text{D} \rightarrow \text{E}}                  (-Δ\text{H}_3) -----(3)

This step converts all the D intermediates formed from step (2) to E. This results in the overall equation of \text{A} \rightarrow 2\text{C} +\text{E}, which is also the equation of interest.

Adding all three together:

\text{A} \rightarrow 2\text{C}+\text{E}            (\bf{\Delta\text{H}_1+2\Delta\text{H}_2-\Delta\text{H}_3 })

Thus, the first option is the correct answer.

Supplementary:

To learn more about Hess's Law, do check out: brainly.com/question/26491956

4 0
1 year ago
I need help with this definitions!!!
abruzzese [7]
Rock cycle - a process in which a rock forms, changes from one type of rock to another, forms again by processes on and in the Earth.

Metamorphic Rock - Rocks changed by intense heat or extreme pressure.

Sedimentary Rock - A rock that forms when sediments are compacted and cemented together.

Igneous Rock - A rock that forms when molten rock cools and hardens.
3 0
3 years ago
Help me<br><br> Extra points
aleksley [76]
G: maintain homeostasis
3 0
3 years ago
Read 2 more answers
A gas has a volume of 3.00 L at 65.0 C. The same gas has a volume of 11.4 L at 105 C and 1725 mmHg. What was the original pressu
velikii [3]
Mm yes diirjrjejekeiejebenwkowe
8 0
3 years ago
For snap
eimsori [14]
Molar mass Li2CO3 = 73.89 g/mol
Mol Li2CO3 = 67.5/73.89 =0.91 mol
Mol LiOH = 1.82 mol
Mark it brainliest please?
3 0
3 years ago
Other questions:
  • How many moles of atoms are in 2.00 g of 13c?
    12·2 answers
  • How many moles are in 3.01 x 10 atoms of magnesium
    13·1 answer
  • Calculate the number of vacancies per cubic meter for some metal, M, at 773°C. The energy for vacancy formation is 0.97 eV/atom,
    10·1 answer
  • A person's blood alcohol (C2H5OH) level can be determined by titrating a sample of blood plasma with a potassium dichromate solu
    14·1 answer
  • A 65.0-gram sample of some unknown metal at 100.0° C is added to 177.1 grams of water at 24.5° C. The temperature of the water r
    8·1 answer
  • What are the subatomic particles of barium
    8·1 answer
  • Wht is 30.00 grams of H3PO4
    10·1 answer
  • A gas that has a volume of 28 Liters, a Temperature of 318 K, and an unknown pressure initially
    7·1 answer
  • Question 3
    9·1 answer
  • What is the frequency of yellow light, which has a wavelength of 5.56 x 10^-7 m?
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!