Answer:
It changed from unsaturated to saturated solution
Explanation:
Before adding the spatula tip full amount, the solution was unsaturated, but as soon as the spatula tip full amount was added and couldn't dissolve, it became unsaturated because it could not dissolve any more solute having already dissolved it maximum number of solute
Explanation:
A freezing point is defined as the point in which a liquid state of a substance changes into solid state.
Whereas boiling point is defined as the point at which liquid state of substance starts to convert into vapor state.
So, a substance is freezing at 
and boils at 
then it means at room temperature, that is, around 
the substance is present in liquid state.
This is because between the freezing and boiling point a substance will always exist in liquid state.
Thus, we can conclude that state of the material at room temperature is liquid.
K2Cr2O7 + 14HCl → 2CrCl3 + 2KCl + 3Cl2 + 7H2O
the correct option is :
K2Cr2O7, because the oxidation number of Cr changes from +6 to +3.
<u>Oxidation number of Cr in K2Cr2O7 is:</u>
K2Cr2O7 = 2K + 2 Cr + 7 O
= 2(+1) + 2Cr + 7(-2)
= 2 + 2Cr -14
[total charge on K2Cr2O7 = 0], Hence;
2 + 2Cr -14 = 0
2Cr -12 = 0
2Cr = 12
Cr = 12/2
<u>Cr = +6</u>
<u>Oxidation number of Cr in CrCl3 is:</u>
CrCl3 = Cr + 3Cl = 0
Cr + 3(-1) = 0
Cr -3 = 0
<u>Cr = +3</u>
Hence Cr is changing its oxidation number from
+6 in K2Cr2O7 to +3 in CrCl3.
Since the oxidation number of Cr [ +6 → +3] is decreasing here,
Cr is getting reduced.
so K2Cr2O7 is an oxidizing agent,as it is getting itself reduced and oxidizes others.
Answer:
Option C
Explanation:
The heat released by the system is absorbed by the surroundings, then only the heat will be balanced.
The surrounding heat increases and so to balance that heat the system releases heat so that it can cool down because heat is neither created nor destroyed.
This is the first law of thermodynamics.
The x number in ^x indicates the number of electronics in an obit, e.g. 1s^2 means there are 2 electrons in the 1s orbit.
Total number of electrons in A = 2 + 2 + 6 +2 + 6 + 2 + 2
= 22
VALENCE electrons are those in the outer most shell.
In A, there are 4s^2 + 4p^2: 2 + 2 = 4
Answer should be C instead. So sorry for the mistake earlier!
