Answer:
325mg of Aspririn
Explanation:
First you should note the information that the problem gives you:
- The bottle of Aspirin has 5gr (grains)
- 1gr(grain) = 65mg (miligrams)
Also, the problem is asking about how many aspirin are in 5 gr (grains), so you should use a conversion factor, as follows:
-First you should put the quantity you need to convert:
-Then you write the denominator of the conversion factor that must have the same units that you want to convert, in this case gr:
-Then you write the numerator with the units that you want to obtain and the numerical equivalence between the units, in this case:
-Finally you multiply numerators and divide by denominators:
Answer:
5.00×10-19 J
Explanation:
E = hv
but v = c ÷ wavelength
E = (6.626×10-34) × ((3×10^8)÷(398×10-9))
= 4.9945×10-19
≈5.00×10-19
Hope this helps
Answer:
B
Explanation:
exo - thermic exo as external thermo like thermometer
external heat....heat is produced and given off
<u>Answer:</u> The volume of HBr solution required is 130.16 mL
<u>Explanation:</u>
To calculate the concentration of base, we use the equation given by neutralization reaction:
where,
are the n-factor, molarity and volume of acid which is 
are the n-factor, molarity and volume of base which is 
We are given:
Putting values in above equation, we get:
Hence, the volume of KOH solution required is 130.16 mL
Radioactive decay => C = Co { e ^ (- kt) |
Data:
Co = 2.00 mg
C = 0.25 mg
t = 4 hr 39 min
Time conversion: 4 hr 39 min = 4.65 hr
1) Replace the data in the equation to find k
C = Co { e ^ (-kt) } => C / Co = e ^ (-kt) => -kt = ln { C / Co} => kt = ln {Co / C}
=> k = ln {Co / C} / t = ln {2.00mg / 0.25mg} / 4.65 hr = 0.44719
2) Use C / Co = 1/2 to find the hallf-life
C / Co = e ^ (-kt) => -kt = ln (C / Co)
=> -kt = ln (1/2) => kt = ln(2) => t = ln (2) / k
t = ln(2) / 0.44719 = 1.55 hr.
Answer: 1.55 hr
