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PtichkaEL [24]
3 years ago
10

Why were gold and copper the first forms of matter investigated by humans

Chemistry
1 answer:
baherus [9]3 years ago
8 0
They were valuable to the eyes of man then.
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Which best describes the trends in electronegativity on the periodic table?
Wittaler [7]

Answer:

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Explanation:

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Coke is an impure form of carbon that is often used in the in-dustrial production of metals from their oxides. if a sample of co
olasank [31]
The reaction equation is:
<span>2CuO(s) + C(s) </span>→ <span>2Cu(s) + CO</span>₂<span>(g)

First, we determine the number of grams present in one ton of copper oxide. This is:
1 ton = 9.09 x 10</span>⁵ g

We convert this into moles by dividing by the molecular mass of copper oxide, which is:
9.09 x 10⁵ / 79.5 = 11,434 moles

Each mole of carbon reduces two moles of copper oxide, so the moles of carbon required are:
11,434 / 2 = 5,717 moles of Carbon required

The mass of carbon is then:
5,717 x 12 = 68,604 grams

The mass of coke is:
68,604 / 0.95 = 72,214 g

The mass of coke required is 7.22 x 10⁴ grams
5 0
3 years ago
*please help*
mojhsa [17]

Answer:

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Explanation:

5 0
3 years ago
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Identify the smaller
pochemuha

Answer:

sub-particle      charge         mass

protons                  +1                 1

neutron                   0                 1

electron                - 1            negligible

protons and neutrons are found in the nucleus

electrons in the shells orbiting the nucleus

3 0
3 years ago
You are requested to reduce the size of 50 ton/hr of a given solid. The size of the feed is such 80% passes a 4-in (76.2 mm) scr
defon

Answer:

1) The power needed to process 50 ton/hr is 135.4 HP.

2) The void fraction of the bed is 0.37.

Explanation:

1) For this type of milling operations, we can estimate the power needed for an operation according to the work index (Ei), the passing size of the circuit feed (F80) and the passing size of the product (P80).

We assume the units of Ei are kWh/t.

The equation that relates this parameters and the power is (size of particles in μm):

W=Ei*(\frac{10}{\sqrt{P80}} -\frac{10}{\sqrt{F80}} )\\\\W=9.45*(\frac{10}{\sqrt{3175\mu m}} -\frac{10}{\sqrt{76200mm}} )\\\\\\W=9.45*(0.1774+0.0362)=2.019 kWh/t

The power needed to process 50 ton/hor is

P=2.0194\frac{kWh}{Ton}*\frac{50Ton}{h}*\frac{1.341HP}{1kW}=   135.4 \, HP

2) The density of the packed bed can be expressed as

\rho=f_v*\rho_v+f_s*\rho_s

being f the fraction and ρ the density of every fraction. We know that the density of the void is 0 (ρv=0) and that fv=1-fs (the sum  of the fractions ois equal to the total space).

Then we can rearrange

\rho=f_v*\rho_v+f_s*\rho_s\\\\\rho=f_v*0+(1-f_v)*\rho_s\\\\\rho/\rho_s=1-f_v\\\\f_v=1-\rho/\rho_s=1-990/1570=1-0.63=0.37

The void fraction of the bed is 0.37.

6 0
3 years ago
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