Answer:
- Question 19: the three are molecular compounds.
Explanation:
<em>Question 19.</em>
All of them are the combination of two kinds of different atoms in fixed proportions.
- C₂H₄: two carbon atoms per four hydrogen atoms
- HF: one hydrogen atom per one fluorine atom
- H₂O₂: two hydrogen atoms per two oxygent atoms
Thus, they all meet the definition of compund: a pure substance formed by two or more different elements with a definite composition.
Molecular compounds are formed by covalent bonds and ionic compounds are formed by ionic bonds.
Two non-metal elements, like H-F, C - C, C - H, H-O, H - H, and O - O will share electrons forming covalent bonds to complete their valence shell. Thus, the three compounds are molecular and not ionic.
<em>Question 20. </em>Formula of copper(II) sulfate hydrate with 36.0% water.
Copper(II) sulfate is CuSO₄. Its molar mass is 159.609g/mol
Water is H₂O. Its molar mass is 18.015g/mol
Calling x the number of water molecules in the hydrate, the percentage of water is:
From which we can solve for x:
Thus, there are 5 molecules of water per each unit of CuSO₄, and the formula is:
The reaction of perchloric acid and barium hydroxide yields to barium perchlorate (Ba(ClO4)2) and water (H2O). The resulting balanced equation is 2 HClO4 + Ba(OH)2 = Ba(ClO4)2 +2 H2O. This means, for every mole of barium perchlorate produced, 2 moles of perchloric acid and barium hydroxide are required.
First you need to know what is a semantic memory
Semantic memory, is a more structured record of facts, meanings, concepts and knowledge about the external world that we have acquired.
So ,The element which is a semantic memory is learning from her father that salt water is more dense than fresh water.
Hope this helped :)
The coefficients are 12, 1, 4, 6
Answer:
Option(II) and option (IV) are correct.
Explanation:
Here products are and and reactant is
(I) According to Le-chatelier principle,increase in will shift the equilibrium towards reactant side to keep the equilibrium constant unchanged.
(II) According to Le-chatelier principle,decrease in will shift the equilibrium towards product side to keep the equilibrium constant unchanged.
(III) Adding a catalyst will not change position of equilibrium. Catalyst only helps to achieve equilibrium in a lesser time.
(IV) As this reaction is an endothermic reaction therefore heat is consumed in formation of product. Therefore increase in temperature will lead to formation of more product to consume excess heat added.
(V) Pure solids and liquids do not affect position of equilibrium as their concentrations remain unchanged.