Answer:
1.0 x 10⁻⁹ M OH⁻.
Explanation:
∵ [H₃O⁺][OH⁻] = 10⁻¹⁴.
[H₃O⁺] = 1.0 x 10⁻⁵ M.
<em>∴ [OH⁻] = 10⁻¹⁴/[H₃O⁺] </em>= 10⁻¹⁴/(1.0 x 10⁻⁵ M) = <em>1.0 x 10⁻⁹ M.</em>
<em>So, the right choice is: 1.0 x 10⁻⁹ M OH⁻.</em>
Answer:
Tube 2 has a total dilution of 1:50
Explanation:
We have a 2 ml serum sample added to a 18 mL phosphate buffered saline sample in tube 1. This means now in tube 1 there is 20 mL.
We have a 1:10 (= 2:20) dilution here.
10 ml of this 1:10 diluted tube 1 is taken and added to a 40 mL of PBS in tube 2.
Now we have 50 mL in tube 2.
This is a 10:50 (= 1:5) dilution.
The total dilution is 10x5 = 50
So the total ditultion has a rate 1:50
Tube 2 has a total dilution of 1:50
Mass of PH3= 6.086 g
<h3>Further explanation</h3>
Given
6.0 L of H2
Required
mass of PH3
Solution
Reaction
P4 + 6H2 → 4PH3
Assumed at STP ( 1 mol gas=22.4 L)
Mol of H2 for 6 L :
= 6 : 22.4 L
= 0.268
From the equation, mol PH3 :
= 4/6 x moles H2
= 4/6 x 0.268
= 0.179
Mass PH3 :
= 0.179 x 33,99758 g/mol
= 6.086 g
Answer:
d) cut the large sized Cu solid into smaller sized pieces
Explanation:
The aim of the question is to select the right condition for that would increases the rate of the reaction.
a) use a large sized piece of the solid Cu
This option is wrong. Reducing the surface area decreases the reaction rate.
b) lower the initial temperature below 25 °C for the liquid reactant, HNO3
Hugher temperatures leads to faster reactions hence this option is wrong.
c) use a 0.5 M HNO3 instead of 2.0 M HNO3
Higher concentration leads to increased rate of reaction. Hence this option is wrong.
d) cut the large sized Cu solid into smaller sized pieces
This leads to an increased surface area of the reactants, which leads to an increased rate of the reaction. This is the correct option.
Answer:
C₂H₄O
CH₃CHO
Explanation:
I'm not sure if you want the molecular formula or the condensed structure, but I will give you both.
Molecular formula:
You have 2 carbons (C₂), 4 hydrogens (H₄), and 1 oxygen (O). The molecular formula will be C₂H₄O.
Condensed Structure:
You have a carbon bonded to three hydrogens (CH₃). This carbon is bonded to a carbon that is bonded to a hydrogen and oxygen (CHO). The condensed structure will be CH₃CHO.
