Answer:
3.0 moles.
Explanation:
- It is a stichiometry problem.
- The chemical reaction of reacting hydrogen with oxygen to produce water is:
<em>H₂ + 1/2 O₂ → H₂O.</em>
- It is clear that <em><u>1.0 mole of H₂</u></em> reacts with 0.5 mole of O₂ to produce <u><em>1.0 mole of water</em></u>.
- The ratio of the reacting hydrogen to the produced water is 1:1.
∴ The number of moles of water created from reacting 3.0 moles of hydrogen completely with excess oxygen = 3.0 moles.
Any deviation in the image of an object when light passing from one medium to other is assciated to the phenomenon of refraction.
<h3>What is refraction ?</h3>
It is the deflection from a straight path undergone by a light ray while passing from one medium (such as air) into another (such as glass) in which its velocity is different.
Basically, the light refraction gives the pencil a slight magnifying effect, which makes the angle appear bigger than it actually is, causing the pencil to look crooked.
<h3 />
- After Looking at the pencil from the side of a clear glass or resealable plastic bag filled three-fourths with water, we will see the light bends around the pencil, causing it to look bent in the water.
- When the pencil tilt from side to side, It looks so dramatically broken on looking at it from different angles.
We can magically “fix” the broken pencil by changing where the pencil is positioned in the glass.
Learn more about Light here;
brainly.com/question/22216162
#SPJ1
A. An Interdependent system of plants, animals, and land
Answer : The time required for decay is, 84 days.
Explanation :
Half-life of chromium-51 = 28 days
First we have to calculate the rate constant, we use the formula :



Now we have to calculate the time required for decay.
Expression for rate law for first order kinetics is given by:

where,
k = rate constant
t = time taken by sample = ?
a = let initial activity of the sample = 100
a - x = amount left after decay process = 12.5
Now put all the given values in above equation, we get


Therefore, the time required for decay is, 84 days.
Answer:
25.30 gram
Explanation:
No of moles = given mass / molar mass
No of moles = 63.17/80.06
0.7890 moles
Mass of sulphar = no of moles× molar mass of sulphar
Mass of sulphur = 0.7890×32.065
25.30 gram