Answer:
20.5 × 10²³ molecules of He
Explanation:
Given data:
Number of moles of He = 3.40 mol
Number of molecules of He = ?
Solution:
The given problem will solve by using Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.
The number 6.022 × 10²³ is called Avogadro number.
For example,
18 g of water = 1 mole = 6.022 × 10²³ molecules of water
1.008 g of hydrogen = 1 mole = 6.022 × 10²³ atoms of hydrogen
For 3.40 moles of He:
3.40 mol × 6.022 × 10²³ molecules
20.5 × 10²³ molecules of He
Answer:
A. is the correct choice.
Explanation:
If there are 70.00 g of Oxygen then it would be molecules, in which there is only 1 option with molecules.
<u><em>I am NOT professional. There is a chance I am wrong. Please reply to me if I made a mistake.</em></u>
Answer:
I use to do it so my swings can mainly be quicker
Answer:
0.500 M
Explanation:
The balanced equation for the neutralization reaction is as follows
NaOH + HCl —> NaCl + H2O
Molar ratio of NaOH to HCl is 1:1
Number of moles of NaOH reacted is equal to the number of HCl moles
We can use the following equation
c1v1 = c2v2
Where c1 is concentration and v1 is volume of HCl
c2 is concentration and v2 is volume of NaOH
Substituting the values
1.00 M x 10.0 mL = c2 x 20.0 mL
c2 = 0.500 M
Concentration of NaOH is 0.500 M
D.
Q= m·ΔT·C(specific heat)= n·M·ΔT·C=10,5mol·27 g/mol· 194,5(225-30,5)·0,9=49600J=49,6kJ.