Well when the sun makes water dissaper thats usually evaporation.
The chemical changes is when the plants absorb the energy from the sunlight and convert water and carbon dioxide into sugar and oxygen gas. Physically nothing has changed. The plant still looks the sam changes occur internally these internal changes are chemical in nature.
24.5 / 14 = 1.75
70 / 16 = 4.375
4.375 / 1.75 = 2.5
empirical formula = N2O5
Answer:
25.0 mL
Explanation:
1. Gather the information in one place.
MM: 98.00 74.09
2H3PO4 + 3Ca(OH)2 → Ca3(PO4)2 + 6H2O
m/g: 8.85 15.76
V/mL: 350.0 550
2. Moles of H3PO4
n = 8.85 g × (1 mol/98.00 g) = 0.09031 mol H3PO4
3. Moles of Ca(OH)2
n = 15.76 g × (1 mol/74.09 g) = 0.2126 mol Ca(OH)2
4. Moles of Ca(OH)2 in 25.0 mL Solution
n = 0.2126 mol × (25.0 mL/550 mL) = 0.009 663 mol Ca(OH)2
5. Moles of H3PO4 needed
From the balanced equation, the molar ratio is 2 mol H3PO4: 3 mol Ca(OH)2
n = 0.009 663 mol Ca(OH)2 × (2 mol H3PO4/3 mol Ca(OH)2)
= 0.006 442 mol H3PO4
6. Volume of H3PO4
V = 0.006 442 mol ×( 350.0 mL/0.09031 mol) = 25.0 mL H3PO4
It will take 25.0 mL of the H3PO4 solution to neutralize 25.0 mL of the Ca(OH)2 solution.
