A. Strontium nitrate;
B. Copper (II) bromide;
C. Dinitrogen tetroxide.
Answer:
0.64 g of S
Solution:
The balance chemical equation is as follow,
2 Cu + S ----> Cu₂S
According to equation,
127 g (2 mole) Cu produces = 159 g (1 mole) of Cu₂S
So,
2.54 g Cu will produce = X g of Cu₂S
Solving for X,
X = (2.54 g * 159 g) / 127 g
X = 3.18 g of Cu₂S
Now, it is confirmed that the reaction is 100% ideal. Therefore,
As,
127 g (2 mole) Cu required = 32 g (1 mole) of S
So,
2.54 g Cu will require = X g of S
Solving for X,
X = (2.54 g * 32 g) / 127 g
X = 0.64 g of S
Answer:
b) pH = 9.25
Explanation:
- NH4+(aq) + H2O(l) ↔ NH3(aq) + H3O+(aq)
- NH3 + H2O ↔ NH4+ + OH-
- 2 H2O ↔ H3O+ + OH-
⇒ Kb = [ NH4+ ] * [ OH- ] / [ NH3 ] = 1.86 E-5......from literature
mass balance NH4+:
⇒ M NH4+ = [ NH4+ ] - [ OH- ]
∴ [ NH3 ] ≅ M NH4+ = 0.26 M
⇒ Kb = (( 0.26 + [ OH- ] )) * [ OH- ] / 0.26 = 1.86 E-5
⇒ 0.26 [ OH-] + [ OH- ]² = 4.836 E-6
⇒ [ OH- ]² + 0.26 [ OH- ] - 4.836 E-6 = 0
⇒ [ OH- ] = 1.859 E-5 M
⇒ pOH = - Log ( 1.859 E-5 )
⇒ pOH = 4.7305
⇒ pH = 14 - pOH = 9.269
(A)Nuclear change..............
All photosynthesis eukaryotic cells contain chloroplast that use the radiant energy of sunlight to convert carbon dioxide and water into carbohydrates. As a byproduct of photosynthesis, oxygen gas is also released into the atmosphere through tiny openings in the leaves called stomata
