Answer: 4.96 moles
Explanation:
C5H12 is the chemical formula for pentane, the fifth member of the alkane family.
Given that,
number of moles of C5H12 = ?
Mass in grams = 357.4 g
Molar mass of C5H12 = ?
To get the molar mass of C5H12, use the atomic mass of carbon = 12g; and Hydrogen = 1g
i.e C5H12 = (12 x 5) + (1 x 12)
= 60g + 12g
= 72g/mol
Now, apply the formula
Number of moles = Mass / molar mass
Number of moles = 357.4g / 72g/mol
= 4.96 moles
Thus, 4.96 moles of C5H12 that are contained in 357.4 g of the compound.
A closed container is any container sealed by means of a lid or other device that neither liquid nor vapor will escape from at ordinary temperatures.
“Ordinary” is the answer, hope this helps! :)
Answer: The reactants
Explanation: These are the substances that go into a chemical reaction and start it.
If element X has 59 protons then element X has 59 electrons.
Side note: as long as an element stays an atom the number of protons and electrons will always have the same value.
Answer:
²³⁸₉₂U has 146 neutrons
Explanation:
To know which option is correct, we shall determine the number of neutrons in each case. This can be obtained as follow:
For ²⁴₁₂Mg:
Mass number (A) = 24
Proton number (P) = 12
Neutron number (N) =?
A = P + N
24 = 12 + N
Collect like terms
N = 24 – 12
N = 12
Thus, there are 12 neutrons in ²⁴₁₂Mg
For ⁷⁵₃₃As:
Mass number (A) = 75
Proton number (P) = 33
Neutron number (N) =?
A = P + N
75 = 33 + N
Collect like terms
N = 75 – 33
N = 42
Thus, there are 42 neutrons in ⁷⁵₃₃As
For ¹⁹₉F:
Mass number (A) = 19
Proton number (P) = 9
Neutron number (N) =?
A = P + N
19 = 9 + N
Collect like terms
N = 19 – 9
N = 10
Thus, there are 10 neutrons in ¹⁹₉F.
For ²³⁸₉₂U:
Mass number (A) = 238
Proton number (P) = 92
Neutron number (N) =?
A = P + N
238 = 92 + N
Collect like terms
N = 238 – 92
N = 146
Thus, there are 146 neutrons in ²³⁸₉₂U
Considering the options and the illustration made above, Only ²³⁸₉₂U has the correct number of neutrons written along side.
