<span>Kind of substance besides water:
The best example of hydrogen bonding excluding water is DNA. The two strands of polymers are connected by hydrogen bonds between the nucleotide bases</span>.
Answer:
Valence electrons. they can be used to determine the group of an element.
Explanation:
Answer:
6.82 moles of Fe2O3
Explanation:
Step 1:
Determination of the number of mole of in 450g of CO2.
This is illustrated below:
Molar Mass of CO2 = 12 + (2x16) = 44g/mol
Mass of CO2 = 450g
Number of mole of CO2 =.?
Number of mole = Mass/Molar Mass
Number of mole of CO2 = 450/44 = 10.23 moles
Step 2:
Determination of the number of mole of Fe2O3 needed for the reaction. This is illustrated below:
2Fe2O3 + 3C—> 4Fe + 3CO2
From the balanced equation above,
2 moles of Fe2O3 reacted to produce 3 moles of CO2.
Therefore, Xmol of Fe2O3 will react to produce 10.23 moles of CO2 i.e
Xmol of Fe2O3 = (2x10.23)/3
Xmol of Fe2O3 = 6.82 moles
Therefore, 6.82 moles of Fe2O3 is required.
The reaction between HCl and NaHCO3 will be;
HCl + NaHCO3 = NaCl + CO2 + H2O
The relative formula mass of NaHCO3 is 84 g/mol
Moles of NaHCO3 in 2 g will be; 2/84 =0.0238 moles
The mole ratio of HCl and NaHCO3 is 1;1
Thus, the number of moles of HCl is 0.0238 moles
The volume of HCl will be;
= 0.0238 moles/0.2
= 0.119 liters or 119 cm³
Answer:
Period
Explanation:
horizontal is a period and verticle is a group
