Hydrogen-1, Carbon-13, Nitrogen-15, Fluorine-19, and Phosphorus-31 are the most useful. Out of these, Hydrogen-1 and Carbon-13 in NMR are the most useful nuclei because the these atoms are the most commonly present in organic molecules.
First, we have to get:
1- The heat required to increase T of ice from -50 to 0 °C:
according to q formula:
q1 = m*C*ΔT
when m is the mass of ice = mol * molar mass
= 1 mol * 18 mol/g
= 18 g
and C is the specific heat capacity of ice = 2.09 J/g-K
and ΔT change in temperature = 0- (-50) = 50°C
by substitution:
∴q1 = 18 g * 2.09 J/g-K *50°C
= 1881 J = 1.881 KJ
2- the heat required to melt this mass of ice is :
q2 = n*ΔHfus
when n is the number of moles of ice = 1 mol
and ΔHfus = 6.01 KJ/mol
by substitution:
q2 = 1 mol * 6.01 KJ/mol
= 6.01 KJ
3- the heat required to increase the water temperature from 0°C to 60 °C is:
q3 = m*C*ΔT
when m is the mass of water = 18 g
C is the specific heat capacity of water = 4.18 J/g-K
ΔT is the change of Temperature of water = 60°C - 0°C = 60°C
by substitution:
∴q3 = 18 g * 4.18 J/g-K * 60°C
= 4514 J = 4.514 KJ
∴the total change of enthalpy = q1+q2+q3
= 1.881 KJ +6.01 KJ + 4.514 KJ
= 12.405 KJ
Answer:
The molarity is 0.56
Explanation:
In a mixture, the chemical present in the greatest amount is called a solvent, while the other components are called solutes. Then, the molarity or molar concentration is the number of moles of solute per liter of solution.
In other words, molarity is the number of moles of solute that are dissolved in a given volume.
The Molarity of a solution is determined by:
Molarity is expressed in units (
).
Then you must know the number of moles of Cu(NO₂)₂. For that it is necessary to know the molar mass. Being:
-
Cu: 63.54 g/mol
- N: 14 g/mol
- O: 16 g/mol
the molar mass of Cu(NO₂)₂ is:
Cu(NO₂)₂= 63.54 g/mol + 2*(14 g/mol + 2* 16 g/mol)= 155.54 g/mol
Now the following rule of three applies: if 155.54 g are in 1 mole of the compound, 225 g in how many moles are they?
moles= 1.45
So you know:
- number of moles of solute= 1.45 moles
- volume=2.59 L
Replacing in the definition of molarity:
Molarity= 0.56
<u><em>The molarity is 0.56</em></u><u><em></em></u>
Answer:Methane(CH4) and dioxygen(O2) are the reactants
Carbon dioxide(CO2) and water(H2O) are the products
Explanation:
THE ANSWER IS OPTION B.
B;SOIL FROM EROSION FILLS UP A POND
HOPE THIS HELP
