Answer:
a) 65.74 = 4 significant figures
b) 60.009 = 5 significant figures
c) 66_ = 2 significant figures
d) 65.750 = 5 significant figures
Explanation:
Significant figures or digits is defined as the total number of digits in a number that have meaning and contribute to the precision of the given number.
a) 65.74 = 4 significant figures, all the non-zero figures are considered significant.
b) 60.009 = 5 significant figures, zeros present between non-zero figures are significant.
c) 66_ = 2 significant figures, all the non-zero figures are considered significant.
d) 65.750 = 5 significant figures, all the non-zero figures and the trailing zero after the decimal are significant.
Count the atoms of each element in the reactants and the products. Use coefficients; place them in front of the compounds as needed.
1. c
2. a
3. b
4. f
5. f
6. f
7. t (i think)
8. t (i think)
9. The wood changed chemically from wood to ashes. It is a chemical change because it can not be brought back to original form. (You can't turn ashes to wood again)
Answer:
The molar concentration would have to be 0,81 M.
Explanation:
The osmotic pressure equation is:
where:
: osmotic pressure [atm]
M: molar concentration [M]
R: gas constant 0,08205 [atm.L/mol.°K]
T: absolute temperature [°K]
To solve the problem, we just clear M from the osmotic pressure equation and then replace our data using the appropiate units. Clearing the variable M we have:
We have to use temperature as absolute temperature (in kelvins), T=29+273=302 °K. Now we can replace our values in the equation:
As we can see, all units will be simplified and we'll have the molar concentration in mol/L.