Answer:
The force of gravity between two objects will decrease as the distance between them increases.
Explanation:
Answer:
Explanation:
For the reaction
C2H5OH (l) + 3 O2(g) = 2CO2(g) + 3 H2O
We can calculate the standard molar enthalpy of combustion using the standard enthalpies of formation of the species involved in the reaction according to Hess law:
ΔHºc = 2ΔHºf CO2 (g) + 3ΔHºfH2O(l) - ( ΔHºf C2H5OH (l) - 3ΔHºfO2 (g) )
( we were not give the water state but we know we are at standard conditions so it is in its liquid state )
The ΔHºfs can be found in appropiate reference or texts.
ΔHºc = 2ΔHºf CO2 (g)+ 3ΔHºfH2O(l) - ( ΔHºf C2H5OH (l) -+3ΔHºfO2 (g) )
= [ 2 ( -393.52 ) + 3 ( -285.83 ) ] - [( -276.2 + 0 ) ] kJ
ΔHºc = -1368.33 kJ
Answer:
24.6g of NaCl
Explanation:
Expression of the reaction:
2NaCl → 2Na + Cl₂
Given parameters:
Mass of Cl₂ = 15g
Unknown:
Mass of NaCl = ?
Solution:
To solve this problem, we have to use mole relationships.
Find the number of moles of the mass of the given specie;
Number of moles =
Molar mass of Cl₂ = 2(35.5) = 71g/mol
Number of moles =
= 0.21mole
Now;
From the balanced reaction equation;
1 mole of Cl₂ is produced from 2 moles of NaCl;
0.21 mole of Cl₂ will be produced from 0.21 x 2 = 0.42mole of NaCl
So,
Mass of NaCl = number of moles x molar mass
Molar mass of NaCl = 23 + 35.5 = 58.5g/mol
Mass of NaCl = 0.42 x 58.5 = 24.6g of NaCl
Answer:

Explanation:
Hello,
In this case, since in a dilution process the moles of the solute must remain unchanged, we use the volumes and molarities as shown below:

Clearly, the concentrated solution is 12M and the diluted solution is 0.5 M, thus, the volume of the concentrated solution we should take is:

Best regards.