Answer:
ΔH0reaction = [ΔHf0 CO2(g)] - [ΔHf0 CO(g) + ΔHf0 O2(g)]
Explanation:
Chemical equation:
CO + O₂ → CO₂
Balanced chemical equation:
2CO + O₂ → 2CO₂
The standard enthalpy for the formation of CO = -110.5 kj/mol
The standard enthalpy for the formation of O₂ = 0 kj/mol
The standard enthalpy for the formation of CO₂ = -393.5 kj/mol
Now we will put the values in equation:
ΔH0reaction = [ΔHf0 CO2(g)] - [ΔHf0 CO(g) + ΔHf0 O2(g)]
ΔH0reaction = [-393.5 kj/mol] - [-110.5 kj/mol + 0]
ΔH0reaction = [-393.5 kj/mol] - [-110.5 kj/mol]
ΔH0reaction = -283 kj/mol
Answer:
1.67 ×10²³ atoms of hydrogen present in 2.5 g of water.
Explanation:
Given data:
Mass of water = 2.5 g
Number of hydrogen atoms= ?
Solution:
First of all we will calculate the molar mass of water.
Molar mass of H₂O = 16 +1 ×2 = 18 g/mol
The number of atoms will be determine through the Avogadro number.
The number 6.022×10²³ is called Avogadro number and it is the number of atoms or molecules in one gram of atoms of an element or one gram molecules of a compound.
First of all we will calculate the number of moles of water in 2.5 g.
Number of moles = mass /molar mass
Number of moles = 2.5 g / 18 g/mol
Number of moles = 0.139 mol
The number of molecules of water in 10 g.
0.139 × 6.022×10²³ = 0.837 ×10²³molecules
one water molecule contain two hydrogen atoms. For 0.837×10²³ molecules,
0.837×10²³× 2 = 1.67 ×10²³ atoms
Answer:
Group 5
Explanation:
Electrons are negative. All atoms want an outer shell of 8
In group 5, the atom has 5 electrons in the outer shell, due to this, the atom will gain 3 electrons, giving it a charge of -3.
This is the most negatively charged possible for any group. Due to group 5 being further left than 6, the elements there are more reactive, meaning they are more likelt to gain electrons.
Hope this helps! :-)