<u>Answer:</u>
<em>A negative ∆H means that energy is given off from a reaction
</em>
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<u>Explanation:</u>
If the reaction has negative ∆H value then the reaction is exothermic
If the reaction has positive ∆H value then the reaction is endothermic
When Heat energy is given in the equation itself
If it is present on the left side it means that heat is absorbed and the reaction is Endothermic
If it is present on the right side it means heat is given off and the reaction is exothermic
To move it needs a form of energy and in this case its chemical
Answer: 1.15M
Explanation:
Given that,
Amount of moles of NaOH (n) = ?
Mass of NaOH in grams = 23.0g
For molar mass of NaOH, use the atomic masses: Na = 23g; O = 16g; H = 1g
NaOH = (23g + 16g + 1g)
= 40g/mol
Since, n = mass in grams / molar mass
n = 23.0g / 40.0g/mol
n = 0.575 mole
Volume of NaOH solution (v) = 0.5 L
Concentration of NaOH solution (c) = ?
Since concentration (c) is obtained by dividing the amount of solute dissolved by the volume of solvent, hence
c = n / v
c = 0.575 mole / 0.5L
c = 1.15 M (M stands for molarity and gives the concentration in moles per litres)
Thus, the molarity of the solution is 1.15M
Answer:
2.7
Explanation:
The equation of the reaction is
3 BaCl2 + Al2(SO4)3 = 3 BaSO4 + 2 AlCl3
So, frok the coefficients of the equation, the answer is 2.7
Answer:
from the spaces left between chains when the polymer is
formed.
Explanation:
Polyethylene polymer may be of high or low density. Whether the polymer is of high or low density depends on the arrangement of the polymer chains.
If the polymer chains are close together such that the resultant polymer is crystalline with chains packed closely, we have high density polyethylene.
On the other hand if the chains are not close together and there are spaces left between chains when the polymer is formed, then we have low density polyethylene.
Hence, low density polyethylene gets its name from the spaces left between chains when the polymer is formed.
