Answer:
6 stages
Explanation:
Given:
Copper ore contains:
4.3 wt% water
10.3 wt% CuSO₄
85.3 wt% rock
Feed rate = 11.7 tons per hour
solution produced is to be 10 wt% copper sulfate
90 wt% water
Now,
The CuSO₄ supplied through the feed = 10.3 wt% CuSO₄ × Feed rate
= 0.103 × 11.7
= 1.2051 tons per hour
also,
At each stage 2 tons of solution is collected
therefore,
The CuSO₄ collected in each stage
= weight of solution × 10 wt% copper sulfate
= 2 tons per hour × 0.1
= 0.2 tons per hour
also,
98% of the CuSO₄ is to be recovered
thus,
the amount of CuSO₄ to be recovered
= 0.98 × CuSO₄ supplied through the feed
= 0.98 × 1.2051 tons per hour
= 1.180998
Therefore,
The number of stages required = 
= 
= 5.90499 ≈ 6 stages
A compound is a substance composed of 2 or more chemical elements.
The model does not represent a compound because it shows two atoms of the same element combined. To be a compound the model would need to contain atoms of different element, represented by different colored balls. Therefore, the picture does not represent a compound. :)
Answer:
There was a change in temperature on the surface you were walking on. It is possible that "you" were walking on cool, wet sand and when your parents said it was time to leave, you ran barefoot towards the parking lot (away from the sand) and got a burning coal sensation on your feet.
Explanation:
1) deep trenches
2) active volcanoes
3) arcs of islands along the tectonic boundaries
4) in some cases, mountain ranges
