Answer:
Rb+
Explanation:
Since they are telling us that the equivalence point was reached after 17.0 mL of 2.5 M HCl were added , we can calculate the number of moles of HCl which neutralized our unknown hydroxide.
Now all the choices for the metal cation are monovalent, therefore the general formula for our unknown is XOH and we know the reaction is 1 equivalent acid to 1 equivalent base. Thus we have the number of moles, n, of XOH and from the relation n = M/MW we can calculate the molecular weight of XOH.
Thus our calculations are:
V = 17.0 mL x 1 L / 1000 mL = 0.017 L
2.5 M HCl x 0.017 L = 2.5 mol/ L x 0.017 L = 0.0425 mol
0.0425 mol = 4.36 g/ MW XOH
MW of XOH = (atomic weight of X + 16 + 1)
so solving the above equation we get:
0.0425 = 4.36 / (X + 17 )
0.7225 +0.0425X = 4.36
0.0425X = 4.36 -0.7225 = 3.6375
X = 3.6375/0.0425 = 85.59
The unknown alkali is Rb which has an atomic weight of 85.47 g/mol
Write the chemical equation for reaction
that is
2SO2+O2 --->2SO2
find the moles of SO2 used = moles=mass/molar mass of so2
= 32g/80g/mol=0.4 moles
by use of reacting ratio between SO2 and SO3 which is 2:2 therefore the moles of so3 is also = 0.4 moles
STP 1 mole = 22.4L.
what about 0.4moles
= 0.4 /1 x22.4=8.96 liters
The two elements that have the same properties as sodium are potassium and rubidium .
<h3>What is periodic table?</h3>
The periodic table is an arrangement of the elements in order of increasing atomic number.
From the list, the two elements that have the same properties as sodium are potassium and rubidium .
Proton has an atomic number of 20 and a mass number of 40. The number of electrons is the same as the number of protons. Given that the atomic number is the number of protons present, we have 20 electrons and 20 protons.
Number of neutrons = Mass number - Number of protons
= 40 - 20 = 20 neutrons
Learn more about periodic table:brainly.com/question/11155928
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Answer:
35.9%
Explanation:
The percent volume of the coffee solution can be calculated as follows:
% volume of coffee solution = volume of coffee/total volume of coffee solution × 100
According to this question, a cup of coffee has 71 mL of coffee and 127 mL of water. This means that, the total volume of coffee solution is;
71mL + 127mL = 198mL
% volume = 71/198 × 100
= 0.359 × 100
Percent volume of coffee solution = 35.9%
<u>Answer</u>:
the continents of earth were clustered together in formation that a scientist named Pangaea.
<u>Explanation</u>:
Before 300 million years ago, our earth was not made up of 7 different continent what we have now. Instead it was single huge mass land that was surrounded by a single ocean called Panthalassa. A lot of migration and collision lead to the formation of Pangaea. An Scientist named Albert Wegener gave the name Pangaea. Later, Pangaea was broken into Gondwanaland and Laurasia.These Lands were then divided into 7 continents.
