QUESTION 3

List three properties if the elements that are useful in sorting the elements.

m_a_m_a [10]

Mass, what its made out of, and atomic number

5 0

3 years ago

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Please help , science tho. by the way i have to do 5

kap26 [50]

Answer:

850

Explanation:

It's between 840 and 860

8 0

2 years ago

The useful metal manganese can be extracted from the mineral rhodochrosite by a two-step process.... In the first step, manganes

frez [133]

Answer : The mass of $MnCO_3$ required are, 35 kg

Explanation :

First we have to calculate the mass of $MnO_2$ .

The first step balanced chemical reaction is:

$2MnCO_3+O_2\rightarrow 2MnO_2+2CO_2$

Molar mass of $MnCO_3$ = 115 g/mole

Molar mass of $MnO_2$ = 87 g/mole

Let the mass of $MnCO_3$ be, 'x' grams.

From the balanced reaction, we conclude that

As, $(2\times 115)g$ of $MnCO_3$ react to give $(2\times 87)g$ of $MnO_2$

So, $xg$ of $MnCO_3$ react to give $\frac{(2\times 87)g}{(2\times 115)g}\times x=0.757xg$ of $MnO_2$

And as we are given that the yield produced from the first step is, 65 % that means,

$60\% \text{ of }0.757xg=\frac{60}{100}\times 0.757x=0.4542xg$

The mass of $MnO_2$ obtained = 0.4542x g

Now we have to calculate the mass of $Mn$ .

The second step balanced chemical reaction is:

$3MnO_2+4Al\rightarrow 3Mn+2Al_2O_3$

Molar mass of $MnO_2$ = 87 g/mole

Molar mass of $Mn$ = 55 g/mole

From the balanced reaction, we conclude that

As, $(3\times 87)g$ of $MnO_2$ react to give $(3\times 55)g$ of $Mn$

So, $0.4542xg$ of $MnO_2$ react to give $\frac{(3\times 55)g}{(3\times 87)g}\times 0.4542x=0.287xg$ of $Mn$

And as we are given that the yield produced from the second step is, 80 % that means,

$80\% \text{ of }0.287xg=\frac{80}{100}\times 0.287x=0.2296xg$

The mass of $Mn$ obtained = 0.2296x g

The given mass of Mn = 8.0 kg = 8000 g (1 kg = 1000 g)

So, 0.2296x = 8000

x = 34843.20 g = 34.84 kg = 35 kg

Therefore, the mass of $MnCO_3$ required are, 35 kg

4 0

3 years ago

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If the mass of 3 black beans it's 0.7 what's the mass of one bean?

mamaluj [8]

Answer:0.233333333

Explanation: Let me be!

3 0

3 years ago

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Which sequence of events is required to form a limestone cave where you can walk around and observe cave formations, such as sta

N76 [4]

Answer:

Which sequence of events is required to form a limestone cave where you can walk around and observe cave formations, such as stalactites? (Note: stalactites hang from the ceiling - they have to hold on tight to the roof.)

A geological sequence of events as involving the lowering of the water table to expose cave structures where stalactites and stalagmites form which is described as follows,

Explanation:

1. Acidic percolated water formed cavities of solution beneath the natural water table known as phreatic zone

2. After the passage of time there is a drop in the water table dropped forming caves from cavities

3. These caves, which are air filled voids that contains adequate environment for forming stalactites and stalagmites and where they are found

5 0

3 years ago