Answer:
86 mL
Explanation:
First find the moles of Pb (NO3)2
n=cv
where
c ( concentration)= 0.210 M
v ( volume in L) =0.05
n= 0.210 × 0.05
n= 0.0105
Using the mole ratio, we can find the moles of KCl by multiplying by 2
n (KCl) =0.0105 ×2
=0.021
v (KCl)= n/ c
= 0.021/ 0.244
=0.08606557377
=0.086 L
= 86 mL
<h3>
Answer:</h3>
0.95 atm
<h3>
Explanation:</h3>
We are given;
Initial pressure, P1 = 1.0 atm
Initial temperature, T1 =298 K (25°C + 273)
Initial volume, V1 = 0.985 L
Final temperature, T2 = 295 K (22°C + 273)
Final volume, V2 = 1.030 L
We are required to find final air pressure;
Using the combined gas law;

To get, P2 ;



= 0.95 atm
Therefore, the air pressure at the top of the mountain is 0.95 atm
Answer:
energy is released in the reaction.
Explanation:
Answer: 
Explanation:-
The conversions involved in this process are :

Now we have to calculate the enthalpy change:
![\Delta H=[n\times c_{ice}\times (T_{final}-T_{initial})]+n\times \Delta H_{fusion}+[n\times c_{water}\times (T_{final}-T_{initial})]+n\times \Delta H_{vap}+[n\times c_{steam}\times (T_{final}-T_{initial})]](https://tex.z-dn.net/?f=%5CDelta%20H%3D%5Bn%5Ctimes%20c_%7Bice%7D%5Ctimes%20%28T_%7Bfinal%7D-T_%7Binitial%7D%29%5D%2Bn%5Ctimes%20%5CDelta%20H_%7Bfusion%7D%2B%5Bn%5Ctimes%20c_%7Bwater%7D%5Ctimes%20%28T_%7Bfinal%7D-T_%7Binitial%7D%29%5D%2Bn%5Ctimes%20%5CDelta%20H_%7Bvap%7D%2B%5Bn%5Ctimes%20c_%7Bsteam%7D%5Ctimes%20%28T_%7Bfinal%7D-T_%7Binitial%7D%29%5D)
where,
= enthalpy change = ?
m = mass of water = 459 g
= specific heat of ice = 
= specific heat of water = 
= specific heat of steam = 
n = number of moles of water = 
= enthalpy change for fusion = 6.01 KJ/mole = 6010 J/mole
= enthalpy change for vaporization = 40.67 KJ/mole = 40670 J/mole
Now put all the given values in the above expression, we get:
![\Delta H=[25.5mole\times 36.57J/mol^0C\times (0-(-10))^0C]+25.5mole\times 6010J/mole+[25.5mole\times 75.40J/mol^0C\times (100-0)^0C]+25.5mole\times 40670J/mole+[25.5mole\times 36.04J/gmol^0C\times (125-100)^0c]](https://tex.z-dn.net/?f=%5CDelta%20H%3D%5B25.5mole%5Ctimes%2036.57J%2Fmol%5E0C%5Ctimes%20%280-%28-10%29%29%5E0C%5D%2B25.5mole%5Ctimes%206010J%2Fmole%2B%5B25.5mole%5Ctimes%2075.40J%2Fmol%5E0C%5Ctimes%20%28100-0%29%5E0C%5D%2B25.5mole%5Ctimes%2040670J%2Fmole%2B%5B25.5mole%5Ctimes%2036.04J%2Fgmol%5E0C%5Ctimes%20%28125-100%29%5E0c%5D)
(1kJ = 1000 J)
Therefore, the enthalpy change is 
Since the mass of a single popcorn kernel is not given, lets us assume that it is 1 gram
Now:
1 mole of popcorn kernels contain
kernels
Since:
1 kernel weighs 1 gram
Then,
kernels would weigh
grams