8.1moles
Explanation:
Given parameters:
Mass of water to be decomposed = 29.2g
Unknown:
Number of moles of oxygen.
Solution:
To solve this problem, we first write the balanced reaction equation :
2H₂O → 2H₂ + O₂
Now convert the given mass of the water to number of moles;
Number of moles of water = 
Molar mass of water = 2(1) + 16 = 18g/mol
Number of moles of water = 
= 16.2moles
From the balanced reaction equation:
2 moles of water produced 1 mole of oxygen gas;
16.2 mole of water will produce 
= 8.1moles of oxygen gas
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Explanation:
It is known that 1 gram contains 1000 milligrams. And, mathematically we can represent it as follows.
or 
So, when we have to convert grams into milligrams then we simply multiply the digit with 1000. And, if we have to convert a digit from milligrams to grams then we simply divide it by 1000.
Answer:
The mass of 2,50 moles of NaCl is 146, 25 g.
Explanation:
First we calculate the mass of 1 mol of NaCl, starting from the atomic weights of Na and Cl obtained from the periodic table. Then we calculate the mass of 2.50 moles of compound, making a simple rule of three:
Weight NaCl= Weight Na + Weight Cl= 23 g+ 35,5 g= 58, 5 g/ mol
1 mol ------ 58, 5 g
2,5 mol---x= (2,5 mol x 58, 5 g)/ 1 mol = <u>146, 25 g</u>
There are 18. In each molecule of Fe(NO3)2 there are 6 oxygen atoms because you have 2 nitrate (NO3) components which each contain 3 oxygen atoms. 2 x 3 = 6. Because you have 3 molecules of Fe(NO3)2, you need to multiply 6 by 3, which gives you 18 oxygen atoms.
The answer is true
Refraction is an effect that occurs when a light wave, incident at an angle away from the normal, passes a boundary from one medium into another in which there is a change in velocity of the light.The wavelength decreases as the light enters the medium and the light wave changes direction.
