Answer:
ΔH°rxn = -47 kJ
Explanation:
Using Hess´s law for the reaction:
3 Fe2O3(s) + CO(g) → 2 Fe3O4(s) + CO2(g) ,
the ΔH°rxn will be given by the expression:
ΔH°rxn kJ = 2ΔHºf(Fe3O4) + ΔHºf(CO2) - ( 3ΔHºf(Fe2O3) + ΔHºf(CO) )
= 2(-1118) + (-394) - ( 3( -824 ) + ( -111 ) )
= - 47 kJ
Answer:
<h3>The answer is 196 g</h3>
Explanation:
The mass of a substance when given the density and volume can be found by using the formula
mass = Density × volume
From the question we have
mass = 56 × 3.5
We have the final answer as
<h3>196 g</h3>
Hope this helps you
Answer:
Mass = 240 g
Explanation:
Given data:
Number of molecules of NaOH = 3.618 × 10²⁴ molecules
Mass in grams = ?
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 NaOH:
1 mole = 6.022 × 10²³ molecules
3.618 × 10²⁴ molecules × 1 mol / 6.022 × 10²³ molecules
0.6 × 10¹ moles
6 moles
Mass of NaOH:
Mass = Number of moles × molar mass
Mass = 6 mol × 40 g/mol
Mass = 240 g
Calcium chloride because it makes three ions for every one compounds. Colligative properties are affected by moles of substance that disrupt the surface tension. Sodium chloride makes only two and molecular substances don't dissociate
