Answer:
1.13×10^25 molecules of water.
Explanation:
Equation of the reaction;
C8H18(g) + 25/2 O2 (g) -------> 8CO2(g) + 9H2O(l)
It is important to first put down the balanced reaction equation. It is not possible to solve any problem on stoichiometric relationship without a balanced reaction equation. Once the equation is obtained, we can now proceed with other steps in the solution of the problem.
From the reaction equation, 1 mole of C8H18 produces 9 moles of water
1 mole of C8H18 occupies 22.4L volume while 1 mole of water contains 6.02×10^23 molecules of water
Hence
22.4 L of C8H18 produces 9(6.02×10^23) molecules of water
46.72 L of C8H18 will produce 46.72 L × 9(6.02×10^23) molecules of water/22.4 L
= 113×10^23 or 1.13×10^25 molecules of water.
Answer:
Elements having same valence electrons are placed in <u>same group.</u>
Explanation:
First, let's start with some basic concepts of modern periodic table:
1. Modern Periodic table : It is the arrangement of element in the increasing order of their atomic numbers
The Modern periodic table is divided into Periods and groups .
Periods : These are the horizontal rows. There are seven periods in the periodic table . Period 1 has 2 element. Period two and three has 8 elements , period 4 and 5 have 18 elements and the period 6 and 7 have 32 elements.
Same period have same number of atomic orbital(Shell)
Group : The group is the vertical columns . There are 18 groups in the modern periodic table.Those element which have same group number will also have same number of electron in their outermost shell. The number of electron in the outermost shell determines the valency of the element.
So, elements showing same valency are placed in same group.
All alkali are place in group 1 and have 1 valance electron in the outermost shell
Use the equation q=ncΔT.
q= heat absorbed our released (in this case 1004J)
n= number of moles of sample ( in this case 2.08 mol)
c=molar heat capacity
ΔT=change in temperature (in this case 20°C)
You have to rewrite the equation for c.
c=q/nΔT
c=1004J/(2.08mol x 20°C)
c=24.1 J/mol°C
I hope this helps
Covalent Bond.
To be specific, it is polar covalent bond. :)
