Given the density of ethanol = 0.79
Volume of ethanol = 75.0 mL
Calculating the mass if ethanol from density and volume:

Molar mass of ethanol = (2*atomic weight of C)+(6*atomic weight of H)+(1*atomic weight of O)
=(2*12g.mol) + (6*1g/mol) + (1*16g/mol)
=46g/mol
Moles of ethanol = 
Volume of the solution = 250.0 mL
Converting the volume from mL ot L:

Molarity of ethanol in the solution = 
Explanation:
Defining law of definite proportions, it states that when two elements form more than one compound, the ratios of the masses of the second element which combine with a fixed mass of the first element will always be ratios of small whole numbers.
A. One of the oxides (Oxide 1) contains 63.2% of Mn.
Mass of the oxide = 100g
Mass of Mn = 63.2 g
Mass of O = 100 - 63.2
= 36.8 g
Ratio of Mn to O = 63.2/36.8
= 1.72
Another oxide (Oxide 2) contains 77.5% Mn.
Mass of oxide = 100 g
Mass of Mn = 77.5 g
Mass of O = 100 - 77.5
= 22.5 g
Ratio of Mn to O = 77.5/22.5
= 3.44
Therefore, the ratio of the masses of Mn and O in Oxide 1 and Oxide 2 is in the ratio 1.72 : 3.44, which is also 1 : 2. So the law of multiple proportions is obeyed.
B.
Oxide 1
Mass of Mn per 1 g of O = mass of Mn/mass of O
= 77.5/22.5
= 3.44 g/g of Oxygen.
Oxide 2
Mass of Mn per 1 g of O = mass of Mn/mass of O
= 77.5/22.5
= 3.44 g/g of Oxygen.
Answer:
A scientific question is basically a question that can lead to a hypothesis to help us figure out the observation in science. I hope this helps you
Answer:
The strength of electric force depends on the amount of electric charge on the particles and the distance between them. Larger charges or shorter distances result in greater force.
Explanation: