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
Answer:
1. A
2. B
Explanation:
1. Most of the answers don't make that much sense, so using process of elimination I resulted in this answer. I recommend you also try to check with others.
2. This question also was pretty confusing but when using process of elimination I resulted in either A or B. To me B makes more sense.
Answer:
298.15 K.
Explanation:
Room temperature is generally taken to be 25 °C (around 77 °F). 0 °C is equivalent to 273.15 K, so we add 273.15 to 25 to find that room temperature is around 298.15 K
The on that is considered a physical change is : A. Sawing a piece of wood in half
When you cut a piece of wood, the chemical compound within the wood will not change at all, which mean that it's a physical change
hope this helps
