There are 9.8 moles of sodium (Na) in a sample of 5.87 x 10²⁴ atoms of sodium.
<h3>HOW TO CALCULATE NUMBER OF MOLES?</h3>
The number of moles of a substance can be calculated by dividing the number of molecules in the substance by Avogadro's number. That is;
no. of moles = no. of atoms ÷ 6.02 × 10²³
According to this question, there are 5.87 x 10²⁴ atoms of sodium. The number of moles is as follows:
no. of moles = 5.87 x 10²⁴ atoms ÷ 6.02 × 10²³
no. of moles = 0.98 × 10¹
no. of moles = 9.8moles
Therefore, there are 9.8 moles of sodium (Na) in a sample of 5.87 x 10²⁴ atoms of sodium.
Learn more about no. of moles at: brainly.com/question/14919968
Answer:
c = 0.898 J/g.°C
Explanation:
1) Given data:
Mass of water = 23.0 g
Initial temperature = 25.4°C
Final temperature = 42.8° C
Heat absorbed = ?
Solution:
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
Specific heat capacity of water is 4.18 J/g°C
ΔT = 42.8°C - 25.4°C
ΔT = 17.4°C
Q = 23.0 g × × 4.18 J/g°C × 17.4°C
Q = 1672.84 j
2) Given data:
Mass of metal = 120.7 g
Initial temperature = 90.5°C
Final temperature = 25.7 ° C
Heat released = 7020 J
Specific heat capacity of metal = ?
Solution:
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
ΔT = 25.7°C - 90.5°C
ΔT = -64.8°C
7020 J = 120.7 g × c × -64.8°C
7020 J = -7821.36 g.°C × c
c = 7020 J / -7821.36 g.°C
c = 0.898 J/g.°C
Negative sign shows heat is released.
<span>3 AgNO3 + FeCl3 = Fe(NO3)3 + 3 AgCl
moles AgNO3 = 18.0 g/ 169.87 g/mol=0.106
moles FeCl3 required = 0.106/3=0.0353
mass FeCl3 = 162.206 g/mol x 0.353 mol=5.73 g
mass FeCl3 in excess = 32.4 - 5.73 =26.7 g.
26.7 gram of excess reactant remain after the reaction is over</span>
Answer:
(a) CH₃CH₂CH₂CH₂CH₂OH
(b) CH₃OH
(c) CH₃CH₂CH₂CH₂CH₂OH
Explanation:
In alcohols, the -OH group is responsible for the polarity. The longer the non-polar hydrocarbon chain, the less polar is the compound.
Regarding solubility, we will consider the general rule "like dissolves like", meaning polar is soluble in polar and non-polar is soluble in non-polar.
(a) I₂ is non-polar, so it will be more soluble in the least polar solvent, which is pentanol (CH₃CH₂CH₂CH₂CH₂OH).
(b) NaCl is an ionic compound, that is, there is a big difference in electronegativity between the atoms. Then, it will be soluble in the most polar alcohol, methanol (CH₃OH).
(c) Pentane (CH₃CH₂CH₂CH₂CH₃) is non-polar, so it will be more soluble in the least polar solvent, which is pentanol (CH₃CH₂CH₂CH₂CH₂OH).