Answer: Chemical change
Explanation:
Physical change is a change in which there is no rearrangement of atoms and thus no new substance is formed. There is only change in physical state of the substance. The change can be reversed using physical methods.
Chemical change is a change in which there is rearrangement of atoms and thus new substance is formed. There may or may not be a change in physical state. The change can only be reversed using chemical methods.
Thus when iron and sulfur are heated in a test tube, the chemical change occurs and thus lead to formation of new substances which could not be separated using magnet.
Answer:
41.44 g
Explanation:
First of all, we must put down the equation of the reaction;
Number of moles of CaO = 33g/56 g/mol = 0.59 moles
Number of moles of H20 = 10g/18 g/mol = 0.56 moles
Since the reaction is in 1:1 mole ration, H2O is the limiting reactant
Hence;
mass of Ca(OH)2 produced = 0.56 moles * 74 g/mol = 41.44 g
Conjugate base of Propanoic acid (
is propanoate where -COOH group gets converted to -CO
. The structure of conjugate base of Propanoic acid is shown in the diagram.
The 
above which 90% of the compound will be in this conjugate base form can be determined using Henderson's equation as propanoic acid is weak acid and it can form buffer solution on reaction with strong base.
= 
+ log![\frac{[Conjugate base]}{[acid]}](https://tex.z-dn.net/?f=%5Cfrac%7B%5BConjugate%20base%5D%7D%7B%5Bacid%5D%7D)
=4.9+log
=5.85
As 90% conjugate base is present, so propanoic acid present 10%.
Answer:
trigonal pyramidal
Explanation:
In NF3, the nitrogen atom is sp3 hybridized. Now we must remember that according to the VSEPR theory, the number of electron pairs in the valence shell of the central atom in a molecule determines its shape.
Here, the nitrogen atom is the central atom and its outermost shell is surrounded by four electron pairs - one lone pair and three bond pairs. This means that it has a tetrahedral electron pair geometry.
However, due to the lone pair, the three fluorine atoms are arranged in a trigonal pyramidal geometry. Hence the correct shape of the molecule is trigonal pyramidal.
Explanation is in a file
bit.
ly/3a8Nt8n
