Answer:
Balanced forces are those two forces acting in opposite directions on an object, and they are equal in size. Anytime if there is a balanced force on an object, the object stays still or it continues moving at the same speed and in the same direction is called a balanced force.
Explanation:
The reaction between boron sulfide and carbon is given as:
2B2S3 + 3C → 4B + 3CS2
As per the law of conservation of mass, for any chemical reaction the total mass of reactants must be equal to the total mass of the products.
Given data:
Mass of C = 2.1 * 10^ 4 g
Mass of B = 3.11*10^4 g
Mass of CS2 = 1.47*10^5
Mass of B2S3 = ?
Now based on the law of conservation of mass:
Mass of B2S3 + mass C = mass of B + mass of CS2
Mass of B2S3 + 2.1 * 10^ 4 = 3.11*10^4 + 1.47*10^5
Mass of B2S3 = 15.7 * 10^4 g
Answer:
1.54 moles of pure ethanol are present in 750mL of wine
Explanation:
The sort of concentration 12% by volume, means that in 100 mL of solution (wine) 12 mL are pure ethanol
We use the density of pure ethanol to determine the mass:
Ethanol density = Ethanol mass / Ethanol volume
Ethanol density . Ethanol volume = Ethanol mass
0.789 g/mL . 12 mL = 9.47 g of ethanol
Now we can determine the moles: 9.47 g . 1 mol / 46.06 g = 0.205 moles
Now we can make a rule of three:
In 100 mL of solution (wine) we have 0.205 moles of pure ethanol
Then, in 750 mL of solution we may have (750 mL . 0.205) / 100 = 1.54 moles
