Answer:
a) volume of ammonium iodide required =349 mL
b) the moles of lead iodide formed = 0.0436 mol
Explanation:
The reaction is:

It shows that one mole of lead nitrate will react with two moles of ammonium iodide to give one mole of lead iodide.
Let us calculate the moles of lead nitrate taken in the solution.
Moles=molarityX volume (L)
Moles of lead nitrate = 0.360 X 0.121 =0.0436 mol
the moles of ammonium iodide required = 2 X0.0436 = 0.0872 mol
The volume of ammonium iodide required will be:

the moles of lead iodide formed = moles of lead nitrate taken = 0.0436 mol
Answer:

Explanation:
Given,
The density of Helium is 
We need to find the density in Dg/μm
We know that,
1 g = 10 dg
1 cm³ = 10¹² μm³
So,

So, the density of Helium is equal to
.
Time taken = 3 hours
<h3>Further explanation</h3>
Given
speed : 75 mph
distance : 225 miles
Required
time taken
Solution
An equation of constant velocity motion

d = distance = m
v = speed = m / s
t = time = seconds
Input the value :
t = d : v
t = 225 miles : 75 miles/hour
t = 3 hours
The data indicates a direct relationship with a positive slope.
<h3>What is direct relationship?</h3>
Direct relationship is a type of relation in which if one factor increases the other will also increases and vice versa. This data represents direct relationship because the increase occur in one value causes increase of another value so we can conclude that the data indicates a direct relationship with a positive slope.
Learn more about relationship here: brainly.com/question/25862883
Delta waves are associated with a deep sleep~