Answer:
0.4 moles of KOH is required to neutralize 0.4 moles of HNO3.
Explanation:
The equation of the reaction is
KOH(aq) + HNO3(aq) ------> KNO3(aq) + H2O(l)
This is a neutralization reaction. A neutralization reaction is a reaction between an acid and a base to form salt and water only.
Having written the balanced chemical reaction equation, we can now solve the prob!em stoichiometrically.
From the balanced reaction equation;
1 mole of KOH is required to neutralize 1 mole of HNO3
Therefore x moles of KOH is required to neutralize 0.4 moles of HNO3
x= 1×0.4/1 = 0.4 moles
Therefore, 0.4 moles of KOH is required to neutralize 0.4 moles of HNO3.
These questions are all about indirect and direct variation with PV=nRT, the ideal gas equation
Q3.
false, because of PV=nRT, the ideal gas equation if V goes up, P has to go down to equal nRT
Q4. false, if V remains constant, and P and T are constant as moles of gas are added, then something is wrong becse something has to change when stuff is added (V has to go down)
Q5.
PV=nRT
when T and n are constant, (R is the gas constant)
PV=k, aka V=k/P which means inversly proportional
TRUE
Q6.
ggeasy
refer to past question
PV=k
if P is doubled then V has to halve in order to equal k
1/2 times 2=1
volume is halved
Q7. use charles law
V/T=k
so
given
V=4
T= kelvins, so 299
4/299=k
so when temp goes to 22 does V go to 3.95
4/299=3.95/295?
true
because they're equal
Q8
FALSE, must be used in kelvins
T=absolute tempurature in kelvins
Q9
PV=nRT
solve for T
(PV)/(nR)=T
use final volumes and pressures
P=5atm
V=24L
n=1
R=0.082057 atm L/(mol K)
(5atm*24L)/(1mol*0.082057 atm L/mol K)=T
see, if you didn't mess up, the units cancel nicely
T=1462.4
1200 K is closest
Q10
PV/T=constant because moles are constant (supposedly)
V=4L
P=2.08atm
T=275K
so find initial to final is constant
(2.08atm*4L)/(275K)=(Pfinal*2.5L)/(323K)
solve for Pfinal
Pfinal=3.92315 atm
answer is 3.9atm
Merry Christmas
The objects that are rubbed together will create charges among themselves due to friction.
(1) The balloon rubbed with a wool cloth will be charged.
(2) If she comb near a small, uncharged object nothing will change.
(3) This is a scientific investigation because it does not involved a step by step process to answer a scientific query.
Answer:
First confirm the reaction is balanced:
C3H8 + 5O2 --> 3CO2 + 4H20 (3 cabon - check; 8 hydrogen - check; 10 oxygen - check).
a) In the equation there is a 5:1 ratio between propane and oxygen. We also know that number of mole is proportional to pressure and volume. Since pressure is constant (STP) then the volume of O2 is 7.2 * 5 = 36 litres.
b) For a near ideal gas that PV = nRT (combined gas law). So for 7.2 litres propane we find n(propane) = 101.3 * 7.2/8.314*298 ~ 0.29 mole (using metric units throughout for simplicity).
There is a 1:3 ratio between propane and CO2. Therefore 3 * 0.29 = 0.87 mole of CO2 is produced.
MW(CO2) ~ 44 g/mol. Therefore m(CO2) = 44 * 0.87 ~ 38.3 g
c) We know we need more oxygen than propane (due to the 1:5 ratio) so oxygen is the limiting reagent. Again Volume is proportional to number of mole and we see there is a 5:4 ratio between oxygen and water. Therefore the volume of water vapour produced will be (4/5) * 15 = 12 litres.
The other questions use the same technique and will give you some much needed practice.
Explanation:
