Answer:
Explanation:
Question 6 options:
1)
A single replacement reaction takes place because sodium is less reactive than hydroxide ions.
<span>C2H5
First, you need to figure out the relative ratios of moles of carbon and hydrogen. You do this by first looking up the atomic weight of carbon, hydrogen, and oxygen. Then you use those atomic weights to calculate the molar masses of H2O and CO2.
Carbon = 12.0107
Hydrogen = 1.00794
Oxygen = 15.999
Molar mass of H2O = 2 * 1.00794 + 15.999 = 18.01488
Molar mass of CO2 = 12.0107 + 2 * 15.999 = 44.0087
Now using the calculated molar masses, determine how many moles of each product was generated. You do this by dividing the given mass by the molar mass.
moles H2O = 11.5 g / 18.01488 g/mole = 0.638361 moles
moles CO2 = 22.4 g / 44.0087 g/mole = 0.50899 moles
The number of moles of carbon is the same as the number of moles of CO2 since there's just 1 carbon atom per CO2 molecule.
Since there's 2 hydrogen atoms per molecule of H2O, you need to multiply the number of moles of H2O by 2 to get the number of moles of hydrogen.
moles C = 0.50899
moles H = 0.638361 * 2 = 1.276722
We can double check our math by multiplying the calculated number of moles of carbon and hydrogen by their respective atomic weights and see if we get the original mass of the hydrocarbon.
total mass = 0.50899 * 12.0107 + 1.276722 * 1.00794 = 7.400185
7.400185 is more than close enough to 7.40 given rounding errors, so the double check worked.
Now to find the empirical formula we need to find a ratio of small integers that comes close to the ratio of moles of carbon and hydrogen.
0.50899 / 1.276722 = 0.398669
0.398669 is extremely close to 4/10, so let's reduce that ratio by dividing both top and bottom by 2 giving 2/5.
Since the number of moles of carbon was on top, that ratio implies that the empirical formula for this unknown hydrocarbon is
C2H5</span>
Answer:
"nonmetal, nonmetal"
Explanation:
Oxygen is a non metal and Nitrogen is a non metal. It is 8th element of the periodic table. It is located in period 2 and group 16.
Nitrogen lies at the group 15 of the periodic table. Its atomic no is 7. Its valency is 2.
Hence, the correct option is (c) "nonmetal, nonmetal".
Answer:
The molar mass of the unknown gas is 
Explanation:
Let assume that the gas is O2 gas
O2 gas is to effuse through a porous barrier in time t₁ = 4.98 minutes.
Under the same conditions;
the same number of moles of an unknown gas requires time t₂ = 6.34 minutes to effuse through the same barrier.
From Graham's Law of Diffusion;
Graham's Law of Diffusion states that, at a constant temperature and pressure; the rate of diffusion of a gas is inversely proportional to the square root of its density.
i.e
where K = constant
If we compare the rate o diffusion of two gases;
Since the density of a gas d is proportional to its relative molecular mass M. Then;
Rate is the reciprocal of time ; i.e
Thus; replacing the value of R into the above previous equation;we have:
We can equally say:
Answer:
Explanation:
The Ce metal has electronic configuration as follows
[Xe] 4f¹5d¹6s²
After losing 4 electrons , it gains noble gas configuration ,. So Ce ⁺⁴ is stable.
Eu has electronic configuration as follows
[ Xe ] 4 f ⁷6s²
[ Xe ] 4 f ⁷
Its outermost orbit contains 2 electrons so Eu²⁺ is stable. Its +3 oxidation state is also stable.
Ce⁺²
