The HCl added = 1.25 moles
and the moles of Na2HPO4 = 1 mole
Now when acid is added in the given solution of Na2HPO4
One mole of H+ will react with one mole of Na2HPO4 to given one mole of NaH2PO4
Na2HPO4 + H+ ---> NaH2PO4
Now this one mole formed NaH2PO4 will further react with 0.25 moles of H+ left to form 0.25 moles of H3PO4 and 0.75 moles of NaH2PO4 will remain in the solution
So this will result into formation of a buffer of phosphoric acid and NaH2PO4
NaH2PO4 + H+ ---> H3PO4
pKa of H3PO4 = 2.1
so pH = pKa + log [salt] / [acid] = 2.1 + log [0.75 / 0.25] = 2.58
so the pH will be in between 2.1 to 7.2
Answers:
1) <span>Breaking Solvent-Solvent Attractions is an Endothermic Process.
2) </span><span>Breaking Solute-Solute Attractions is an Endothermic Process.
3) </span><span>Forming Solute-Solvent Attractions is an Exothermic Process.
Explanation:
When a solute is dissolved in solvent it either releases heat or absorbs heat depending upon the the interactions broken and interactions formed. At first, the solvent solvent interactions are broken , this process requires heat which is provided either from external source or is provided by the forming of solute solvent bond forming process which is exothermic.
When the solvent molecules get apart the solute particles enter to form interactions with elimination of heat. So, if the heat required to break solvent solvent interactions is greater than the heat provided by solute solvent interactions formation then the solute will not dissolve at room temperature and vice versa.</span>
Answer:
- 6.38x10²² molecules C₆H₁₂O₆
Explanation:
First we <u>convert the given masses into moles</u>, using the <em>compounds' respective molar mass</em>:
- 64.7 g N₂ ÷ 28 g/mol = 2.31 mol N₂
- 83 g CCl₄ ÷ 153.82 g/mol = 0.540 mol CCl₄
- 19 g C₆H₁₂O₆ ÷ 180 g/mol = 0.106 mol C₆H₁₂O₆
Then we multiply each amount by <em>Avogadro's number</em>, to <u>calculate the number of molecules</u>:
- 2.31 mol N₂ * 6.023x10²³ molecules/mol = 1.39x10²⁴ molecules
- 0.540 mol CCl₄ * 6.023x10²³ molecules/mol = 3.25x10²³ molecules
- 0.106 mol C₆H₁₂O₆ * 6.023x10²³ molecules/mol = 6.38x10²² molecules
You should read up on Proust's law, better known as the Law of Definite Proportions. This is a chemical law that defines your question more generally, on why the ratio of elements and ions are always fixed.
Basically, this compound Magnesium(II) Chloride is MgCl2 because it has the same number of protons, neutrons, and electrons all the way. This defines the properties of the compound or atom.
Answer:
0.6 grams of hydrogen are needed to react with 2.75 g of nitrogen.
Explanation:
When hydrogen and nitrogen react they form ammonia.
Chemical equation:
N₂ + 3H₂ → 2NH₃
Given mass of nitrogen = 2.75 g
Number of moles of nitrogen:
Number of moles = mass/ molar mass
Number of moles = 2.75 g / 28 g/mol
Number of moles = 0.098 mol
Now we will compare the moles of nitrogen with hydrogen from balance chemical equation:
N₂ : H₂
1 : 3
0.098 : 3×0.098 = 0.3 mol
Mass of hydrogen:
Mass = number of moles × molar mass
Mass = 0.3 mol × 2 g/mol
Mass = 0.6 g
