Answer:
substance A is water and substance B is chlorophyll
Explanation:
3.25 kg in g = 3.25 * 1000 = 3250 g
Molar mass C₂H₆O₂ = 62.0 g/mol
Mass solvent = 7.75 kg
Number of moles:
n = mass solute / molar mass
n = 3250 / 62.0
n = 52.419 moles
Molality = moles of solute / kilograms of solvent
M = 52.419 / 7.75
M = 6.7637 mol/kg
hope this helps!
A, as carbon is an atomic substance - element
Answer:
Coefficients
Explanation:
Chemical equations are first written as a skeleton equation, which includes how many atoms each element and compound has. Skeleton equations are not 'balanced' because the number of atoms of each element on the left side (reactants) is not equal to the right side (products).
To balance a chemical equation, you can write coefficients in front of single elements and compounds. The coefficient multiplies with each single element and with each element in the compound.
For example, in this skeleton equation:
H₂ + Cl₂ => HCl
Reactants: Products:
2 hydrogen 1 hydrogen
2 chlorine 1 chlorine
Write the coefficient 2 in the products.
H₂ + Cl₂ => 2HCl
Now both reactant and product sides have 2 chlorine and 2 hydrogen, so the equation is balanced.
12 times breathe give 240 ml of pure 
. Each breathe gives 20 ml of .
Let us consider, volume of air per breathe= x ml.
Pure from inhaled air= 
ml and Pure from exhaled air= 
ml.
Pure from inhaled and exhaled air= 20 ml
So, + = 20
Therefore, x = 55.5 ml
So, volume of air per breath= 55.5 ml.
