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
aev [14]
3 years ago
13

How many atoms are in a sample of 72.8 grams calcium ?

Chemistry
1 answer:
MArishka [77]3 years ago
6 0
First find the moles
moles of the calcium= 72.8 / 40
moles of calcium in 72.8g = 1.82mol

number of atoms= moles x Avogadro constant
atoms = 1.82 x 6.02x10+23
so the number of atoms is 1.096x10+24
You might be interested in
Calculate the change in enthalpy for the following reaction, using the bond enthalpy data provided below. (Note: you may round t
aliina [53]

Answer:

-514 kJ/mol

Explanation:

The bond enthalpy which is also known as bond energy can be defined as the amount of energy needed to split one mole of the stated bond. The change in enthalpy of a given reaction can be estimated by subtracting the sum of the bond energies of the reactants from the sum of the bond energies of the products.

For the given chemical reaction, the change in enthalpy of the reaction is:

ΔH_{rxn} = [2(409) + 4(388) + 3(496) - 4(630) - 4(463)] kJ/mol = 818 + 1552 + 1488 - 2520 - 1852 = -514 kJ/mol

3 0
4 years ago
what volume of 1.75 m hcl in liters is needed to react completely (with nothing left over) with 0.750 l of 0.100 m na2co3 ?
Evgesh-ka [11]

The balance chemical equation is :

2HCL + Na2CO3 -----> 2NaCl + H2O + CO2

According to Question,

Given,

Molarity of HCL = 1.75 m

Sodium Carbonate (Na2CO3) = 0.100 m

For finding out the molarity,

c = n solute / Vsolution  => n = c.Vsolution

nCO^2-3 = 0.100 mol L^-1 . 0.750 L = 0.0750 moles of CO^2-3

0.0750 moles of CO^2-3 . 2 moles H3O^+ / 1 mole CO^2-3

= 0.150 moles of  H3O^+

As we have already know the molarity of HCL , we easily calculate what volumes by many moles.

c = nsolute / Vsolution => Vsolution = nsolute / c

VH3O^+ = 0.150 moles / 1.75 mol L^-1 =  0.0857 L

To know more about Molarity here :

brainly.com/question/8732513?referrer=searchResults

#SPJ4

6 0
1 year ago
What is an element?
Marat540 [252]
B. A pure substance made up of one type of atom
8 0
3 years ago
Read 2 more answers
Use the following information S(s)+O2(g)→SO2(g)S(s)+O2(g)→SO2(g), ΔH∘ΔH∘ = -296.8kJkJ SO2(g)+12O2(g)→SO3(g)SO2(g)+12O2(g)→SO3(g)
Sedaia [141]

Answer: The ∆Hf is -384.7kj/mol

Explanation:

H2O +SO3-----H2SO4

-285.8 +(-98.9------- -384.7kj/mol

4 0
3 years ago
Give the Shorthand Electron Configuration for the following elements:
Gnoma [55]

answer of this question is [Ar]3d8 4s2

5 0
3 years ago
Other questions:
  • If you are given 1.709 moles of solute, and you dilute it to make 2.10 liters of solution, what is the resulting molarity (M)? (
    14·1 answer
  • We start with the molecule below instead of palmitic acid, which step will be interrupted and which enzyme will be used to corre
    5·1 answer
  • Ammonia and oxygen react to form nitrogen monoxide and water, like this:
    15·1 answer
  • Identify the limiting reactant in the reaction of nitrogen and hydrogen to form NH3 if 5.23 g of N2 and 5.52 g of H2 are combine
    7·1 answer
  • Examples s name of thosse food items we can store for a month?​
    14·1 answer
  • What intermolecular force attracts two non polar molecules to each other
    12·1 answer
  • List an example of earth landforms changing due to weathering and erosion
    10·1 answer
  • 5.2 X 1026 molecules of CH4
    12·1 answer
  • Drag the item from the item bank to its corresponding match.
    11·1 answer
  • True or False: Passive transport occurs when molecules move from an area of low concentration to high concentration.
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!