Answer:
It is 20. g HF
Explanation:
H2 + F2 ==> 2HF ... balanced equation
Since the question is asking us to find the mass of product formed, we will want to first convert the molecules of H2 into moles of H2 (we could do this at the end of the calculations, but it's just as easy to do it now).
moles of H2 present (using Avogadro's number):
3.0x1023 molecules H2 x 1 mole H2/6.02x1023 molecules = 0.498 moles H2
From the balanced equation, we see that 1 mole H2 produces 2 moles HF. Therefore, we can now find the theoretical mass of HF produced from 0.498 moles H2:
0.498 moles H2 x 2 moles HF/1 mol H2 = 0.996 moles HF formed.
The molar mass of HF = 20.01 g/mole, thus...
0.996 moles HF x 20.01 g/mole = 19.93 g HF = 20. g HF formed (to 2 significant figures)
Answer:
<h3>Therefore, after long period of time 80kg of salt will remain in tank</h3>
Explanation:
given amount of salt at time t is A(t)
initial amount of salt =300 gm =0.3kg
=>A(0)=0.3
rate of salt inflow =5*0.4= 2 kg/min
rate of salt out flow =5*A/(200)=A/40
rate of change of salt at time t , dA/dt= rate of salt inflow- ratew of salt outflow
integrating factor
integrating factor 
multiply on both sides by
integrate on both sides
b)
after long period of time means t - > ∞
<h3>Therefore, after long period of time 80kg of salt will remain in tank</h3>
Answer:
Box is made up of <em>copper</em>, because density is <em>8.96 g/cm³.</em>
Explanation:
Given data:
Volume of box = 17.63 cm³
Mass of box = 158 g
Which metal box is this = ?
Solution:
First we will calculate the density of box then we will compare it with the density value of given metals.
d = m/v
d = 158 g/ 17.63 cm³
d = 8.96 g/cm³
The calculated density is similar to the given density value of copper thus box is made up of copper.
When you are converting grams to moles, the operation that you will be doing is dividing by the molar mass to obtain the amount of moles of the given sample.
