To determine the expected pH of the resulting solution of the following substances, create a balanced chemical equation of their ionization in water:
HI
HI + H2O ---> H+ + I-
It completely dissociates into H+ and I-. Due to the presence of the Hydronium Ion, the solution is acidic.
KBr
KBr + H2O ----> HBr + KOH
The salt KBr is formed by a strong base and a weak acid, therefore, the solution it forms with water is basic.
LiOH
LiOH + H2O ----> Li+ + OH-
It dissociates completely in water, turns into Li+ and OH-. Due to the presence of Hydroxide Ion, the solution becomes basic.
Answer: Penicillin G (also called benzylpenicillin) was discovered by accident in 1928. Alexander Fleming, a Scottish physician-scientist was growing a type of bacteria called Staphylococcus Aureus on an uncovered petri dish when it became contaminated with mold spores.
Explanation:
The balanced chemical reaction is:
CH4 + 2O2 —> CO2 + 2H2O
You need to convert mass to moles (divide by molar mass):
CH4 moles = 5 / 16 = 0.31 mol
O2 moles = 5 / 32 = 0.16 mol
To figure out which reactant is limiting, divide the actual moles by the corresponding coefficient in the reaction:
CH4: 0.31 / 1 = 0.31
O2: 0.16 / 2 = 0.08
O2 is the lower number, so it is the limiting reactant. From the reaction we know it takes 2 moles of O2 to react with each mole of CH4. Therefore, for however many moles of O2 we actually have, half as many moles of CH4 will react. Since we have 0.16 mol of O2, only 0.08 mol of CH4 will react, leaving behind 0.31 - 0.08 = 0.23 mol of CH4.
Now convert back to mass (multiply by molar mass) to find the mass of CH4 remaining:
0.23 x 16 = 3.68g
The closest answer is B.
Answer :
Lewis-dot structure : It shows the bonding between the atoms of a molecule and it also shows the unpaired electrons present in the molecule. The electrons are represented by dot.
The given molecule is, perbromate ion.
Bromine has '7' valence electrons and oxygen has '6' valence electron.
Therefore, the total number of valence electrons in perbromate ion, 
= 7 + 4(6) + 1 = 32
According to Lewis-dot structure, there are 14 number of bonding electrons and 18 number of non-bonding electrons.
Formula for formal charge :
The Lewis-dot structure of perbromate ion is shown below.
