Answer:
B
Explanation:
Frequency and wavelength are inversely proportional
Answer:
13. D Hypothesis 14. A Analyze Matter, Solve Problems
Explanation:
The length, width and height of the wall of room is 12.0 ft, 15.0 ft and 9 ft respectively. To calculate the gallons of paint to paint the room with two coats, first calculate the surface area of room that needs to be coated.
The total surface are of room without ceiling will be:
Here, l is length, h is height and w is width of the room.
Putting the values,
Since, 1 gallon of paint is used for area , for of area, volume of paint used will be 0.00267 gallon.
Thus, volume of paint used for area will be:
The above volume is for 1 coat of paint, for 2 coats volume will be:
Therefore, paint required to paint room with two coats is 2.6 gallon.
Answer:
0.081g
Explanation:
first step:calculate the molar conc of the stock solution
molar conc=mass/molar mass ×1000/vol(ml)
molar mass of Co(N03)2=182.943
molar conc=3g/182.943 ×1000/100ml
=0.163M
To calculate the conc of the resulting solution we apply the dilution principle
n=cv
C1V1=C2V2
C1=conc of stock solution=0.163M
V1=4mL
V2=275ml(final volume)
by making 'C2" the subject C2=0.163×4/275
=0.0024M
by applying the formular for calculating molar conc of a solution,we can calculate the mass of CO(NO3)2 in the reulting solution
molar conc=mass/molar mass ×1000(L)/vol(mL)
mass=0.0024×182.943×275/1000
=0.1193g
Mass of CO(NO3)2 in the resulting solution=0.1199g
since CO+(NO3)2=CO(NO3)2
Percentage by mass of (NO3)2 in CO(NO3)2=(NO3)2/CO(NO3)2
=124/182.943×100
=67.8%
it means 67.8% of 0.1193g is the mass of (NO3)2=0.678×0.1199
=0.081g