Answer:
The final temperature of the water is 22.44°C.
Explanation:
Heat lost by tin will be equal to heat gained by the water

Mass of tin = 
Specific heat capacity of tin = 
Initial temperature of the tin = 
Final temperature =
=T

Mass of water= 
Specific heat capacity of water= 
Initial temperature of the water = 
Final temperature of water =
=T

(Law of Conservation of energy)

On substituting all values:

we get, T = 22.44°C
The final temperature of the water is 22.44°C.
Answer:
Explanation:
<u>1) Determine the molar mass of the heptane</u>
element # of atoms atomic mass total mass
C 7 12.011 g/mol 7×12.011 g/mol = 84.077 g/mol
H 16 1.008 g/mol 16×1.008 g/mol = 16.128 g/mol
-------------------
Molar mass = 100.205 g/mol
<u>2) Percent of carbon, %</u>
- % = (mass of element / molar mass )×100
= (84.077 g/mol / 100.205 g/mol )×100 = 83.83 %
- Round to two significant figures: 84% ← answer
Answer:
278 ml of KOH.
Explanation:
The equation for the reaction is: Pb(NO3)2(aq) + 2KOH(aq) --> Pb(OH)2(s) + 2KNO3(aq)
Pb(NO3)2:
Half ionic equation:
Pb(NO3)2(aq) --> Pb2+ + 2NO3^-
Pb(OH)2 --> Pb2+ + 2OH-
Volume = 135 mL
Molar concentration = 0.775 M
Number of moles = molar concentration * volume
= 0.775 * 0.135
= 0.105 mol of Pb(NO3)2
Since 1 mole of Pb(NO3)2 reacted with 2 moles of KOH to give 1 mole of Pb2+ (Pb(OH)2).
By stoichiometry,
Number of moles of KOH = 0.105 * 2
= 0.21 mol
Molar concentration = number of moles/volume
Volume = 0.21/0.753
= 0.278 l
To ml, 0.278 l * 1000 ml/1l
= 278 ml of KOH.
Answer:
The mass of glycerol that the student should weigh out depends on the volume that is needed. For example, the density of glycerol is 1.26 g/mL. Then, if 500 mL of glycerol is needed, 630 g should be weighed.
Explanation:
Density is the amount of mass per unit of volume. Density relates how many grams 1 milliliter of a substance weighs. Thus, if the density of glycerol is 1.26 g/mL means that 1.26 grams of glycerol occupy 1 mL of volume, or, in other words, 1 mL of glycerol weighs 1.26 grams.
Therefore, if 500 mL of glycerol is required to use for an experiment, 630 grams need to be weighed:
1 mL glycerol________ 1.26 g
500 mL glycerol______ x= 500mL * 1.26 g / 1 mL = 630 g