Liquid 2 because the lower the density the more it floats and the higher the density the more it sinks. The order from top to bottom is liquid 2, liquid 3, liquid 1
Answer:
- (0.1 mol NaH₂PO₄ + 0.1 mol Na₂HPO₄)
Explanation:
A buffer solution is an aqueous solution consisting of a mixture of a weak acid and its conjugate base, or weak base and its conjugate acid.
Also, a buffer solution is a solution which resists changes in pH when acid or alkali is added to it.
- (0.1 mol NaH₂PO₄ + 0.1 mol Na₂HPO₄) when dissolved in 1 L H₂O will produce a buffer because NaH₂PO₄ is considered as weak acid while Na₂HPO₄ is its conjugate base. 2.
- (0.1 mol H₃O⁺ + 0.1 mol Cl⁻) is not a mixture of a weak acid and its conjugate base, or weak base and its conjugate acid.
- (0.1 mol HCl + 0.1 mol NaoH) HCL is a strong acid and NaOH is a strong base so it will not form a buffer when dissolved in water.
- (0.1 mol H₃O⁺ + 0.1 OH⁻) is not a mixture of a weak acid and its conjugate base, or weak base and its conjugate acid
- (0.1 mol NaCl+ 0.1 mol KCl) NaCL and KCL are salts so it will not form a buffer when dissolved in water.
So the right choice is
- (0.1 mol NaH₂PO₄ + 0.1 mol Na₂HPO₄)
Answer:
20 ounces of 14% solution and 8 ounces of 7% solution.
Explanation:
Let the amount of 14% solution required be A and the amount of 7% solution required be B.
Mixture of A and B must give 28 ounces:
A + B = 28 ................. Eqn 1
Also, mixture of 14% A and 7% B must give 12%, 28 ounces solution:
0.14A + 0.07B = 0.12(28) = 3.36...................Eqn 2
From eqn 1, B = 28 - A, eqn 2 becomes:
0.14A + 0.07(28 - A) = 3.36
0.07A = 3.36 - 1.96
A = 20 ounces
Substitute the value of A into eqn 1 to get B:
20 + B = 28
B = 8 ounces.
Hence, 20 ounces of 14% hydrochloric acid and 8 ounces of 7% hydrochoric acid should be mixed together in order to get 28 ounces of 12% solution.
<h3>
Answer:</h3>
54 g
<h3>
Explanation:</h3>
- The reaction between carbon and oxygen gas is given by the equation;
C(s) + O₂(g) → CO₂(g)
We are given;
18 g of Carbon
72 g of Carbon dioxide
- We need to calculate the amount of oxygen needed for the reaction.
- From the law of conservation of mass in chemical equation, the mass of the reactants is equal to the mass of the product.
Therefore;
Mass of Oxygen gas + mass of the carbon = Mass of carbon dioxide
Therefore;
Mass of Oxygen gas = mass of carbon dioxide - mass of carbon
= 72 g - 18 g
= 54 g
Therefore, the mass of Oxygen needed would be 54 g
The correct answer is C. Noble gases. Good luck!
-Melissa ❤️
