Because if you change two things then you do not know which one has affected or altered the dependent variable. if you only change one then you know what exactly changed and why
Answer:
HF
Explanation:
Hf has hydrogen bonding which is the strongest intermolecular forces. The stronger the IM forces, the higher the boiling point.
<h3>
Answer:</h3>
20.62 Kilo-joules
<h3>
Explanation:</h3>
- The Enthalpy of combustion of ethyl alcohol is -950 kJ/mol.
- This means that 1 mole of ethyl alcohol evolves a quantity of heat of 950 Joules when burned.
Molar mass of ethyl ethanol = 46.08 g/mol
Therefore;
46.08 g of C₂H₅OH evolves heat equivalent to 950 kilojoules
We can calculate the amount of heat evolved by 1 g of C₂H₅OH
Heat evolved by 1 g of C₂H₅OH = Molar enthalpy of combustion ÷ Molar mass
= 950 kJ/mol ÷ 46.08 g/mol
= 20.62 Kj/g
Therefore, a gram of C₂H₅OH will evolve 20.62 kilo-joules of heat
Answer:
All are having different valent cation and anion like mono,di and trivalent polyatomic ions .
A. RbNO3
B. K2S
C. NaHS
D. Mg3(PO4)2 formed by divalent Mg+2 and trivalent PO43-
E. CaHPO4
F. PbCO3 , lead is in Pb+2 form
G. SnF2
H. (NH4)2SO4
I. AgClO4
J. BCl3
There are things called "Reactants" and "Products" All chemical equations look something like "A + B →C (+ D...)," in which each letter variable is an element or a molecule (a collection of atoms held together by chemical bonds). The arrow represents the reaction or change taking place. Some equations may have a double-headed arrow (↔), which indicates that the reaction can proceed either forward or backward. When a compound has been written out, you must identify the elements and know their chemical symbols. The first element written is “first name” of the compound. Use the periodic table to find the chemical symbol for the element. So here is an example: Dinitrogen hexafluoride. The first element is nitrogen and the chemical symbol for nitrogen is N. To know the numbers of atoms that are present for each element you can just look at the prefix from the element For example: Dinitrogen has a the prefix “di-“ which means 2; therefore, there are 2 atoms of nitrogen present.
Write dinitrogen as N2.
Now for the second element or "last name" of the compound whatever will follow the first element so like; Dinitrogen hexafluoride. The second element is fluorine. Simply replace the “ide” ending with the actual element name. The chemical symbol for fluorine is F.
But the more you practice with, the easier it will be to decipher chemical formulas in the future and learn the language of chemistry.
Sulfur dioxide: SO2
Carbon tetrabromide: CBr4
Diphosphorus pentoxide: P2O5 ← That is one of the examples I'll give you.
have a gooooood daaaaayy
