Answer:
V1= 0.305L
Explanation:
To find the initial volume of 1.25M potassium fluoride needed to make tge dilution specified in the question, we can use: C1 × V1 = C2 × V2
Since the question wants the volume in litres, convert 455 mL to L
455/ 1000
= 0.455 L
Now make the substitution
1.25 × V1 = 0.838 × 0.455
Rearrange to make V1 the subject
V1=

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
In the reaction of silver nitrate with copper metal, metallic silver comes out of solution, and the solution turns blue. This as a <u>single replacement</u> reaction.
<h3>What is
single replacement reaction?</h3>
A single replacement reaction, also known as a single displacement reaction, occurs when one element in a molecule is swapped out for another. The starting materials are always pure elements, such as a pure zinc metal or hydrogen gas, plus an aqueous compound.
A + BC → B + AC
When A is more reactive than B or when the product AC is more stable than BC, single replacement reactions happen. A and B could either be two halogens or two metals (with hydrogen included) (C is a cation). C functions as a spectator ion when BC and AC are in aqueous solutions.
For example, 2HCl(aq)+Zn(s)→ZnCl₂(aq)+H₂(g)
Learn more about single replacement reactions here:
brainly.com/question/19068047
#SPJ4
protons, neutrons, and electrons.