-20.16 KJ of heat are released by the reaction of 25.0 g of Na2O2.
Explanation:
Given:
mass of Na2O2 = 25 grams
atomic mass of Na2O2 = 78 gram/mole
number of mole = 
= 
=0. 32 moles
The balanced equation for the reaction:
2 Na2O2(s) + 2 H2O(l) → 4 NaOH(aq) + O2(g) ∆Hο = −126 kJ
It can be seen that 126 KJ of energy is released when 2 moles of Na2O2 undergoes reaction.
similarly 0.3 moles of Na2O2 on reaction would give:
= 
x = 
= -20.16 KJ
Thus, - 20.16 KJ of energy will be released.
Answer:
American Holly, Black Pine, Blue Pacific Juniper, Blue Dune Grass, Artemesia) MODERATELY SALT TOLERANT: plants always need protection from salt spray but will tolerate some inundations by storm surges. They are best used behind fences or buildings. (
948 or 9.48 x 10^2
There are two sets of rules for significant figures
• One set for addition and subtraction
• Another set for multiplication and division
You used the set for multiplication and division.
This problem involves addition and subtraction, and the rule is
The number of places after the decimal point in the answer must be <em>no greater than the number of decimal places in every term</em> in the sum.
Thus, we have
78.9
+890.43
-21.
= 948.33
The "21" term has the fewest digits after the decimal point (none), so the answer must have no digits after the decimal point.
To the correct answer is 948 = 9.48 x 10^2. It has three significant figures.
The answer is True . The precision of a measuring is based on the fitness of its scale subdivisions
Answer:
In a nutshell, diet refers to all the food that you consume through the day, on a regular basis. Nutrition, on the other hand, refers to the fuel that your body requires to function optimally and maintain good health. It refers to the right mix of nutrients.
Explanation:
