<span>We can use rocks to determine if the animals from to day have changed from the past.
Rocks also help us know if rivers once flowed through an area.
We use them to find out what type of animals live then that are extinct now.</span>
Answer:
0.393 mol/L.
Explanation:
The following data were obtained from the question:
Number of mole of NaOH = 0.550 mol
Volume of solution = 1.40 L
Molarity of NaOH =.?
Molarity of a solution is simply defined as the mole of solute per unit litre of the solution. Mathematically, it is expressed as:
Molarity = mole /Volume
With the above formula, we can obtain the molarity of the NaOH solution as follow:
Number of mole of NaOH = 0.550 mol
Volume of solution = 1.40 L
Molarity of NaOH =.?
Molarity = mole / Volume
Molarity of NaOH = 0.55 / 1.4
Molarity of NaOH = 0.393 mol/L
Thus, the molarity of the NaOH solution is 0.393 mol/L.
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:
A
Explanation:
I used my resources and they was explaining and I came to a resolution that it was A
D:
When electrons are gained, the charge of the atom decreases.
When you are given an atom with a charge, the oxidation of that atom is the charge. So by going from a Cr^3+ (Oxidation Number = 3) to a Cr^2+ (Oxidation Number = 2), the Oxidation Number thus decreases.
