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fomenos
3 years ago
6

How many elements have been discovered so far by scientists ​

Chemistry
1 answer:
Inessa [10]3 years ago
6 0

Answer:

118 elements have been discovered so far

Explanation:

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For the reaction 2kclo3(s)→2kcl(s)+3o2(g) calculate how many grams of oxygen form when each quantity of reactant completely reac
barxatty [35]
First, we need to get the molar mass of:

KClO3 = 39.1 + 35.5 + 3*16 = 122.6 g/mol

KCl =39.1 + 35.5 = 74.6 g/mol

O2 = 16*2 = 32 g/mol

From the given equation we can see that:

every 2 moles of KClO3 gives 3 moles of O2

when mass = moles * molar mass

∴ the mass of KClO3 = (2mol of KClO3*122.6g/mol) = 245.2 g

and the mass of O2 then = 3 mol * 32g/mol = 96 g

so, 245.2 g of KClO3 gives 96 g of O2

A) 2.72 g of KClO3: 

when 245.2 KClO3 gives → 96 g  O2

   2.72 g KClO3 gives →  X

X = 2.72 g KClO3 * 96 g O2/245.2 KClO3

    = 1.06 g of O2

B) 0.361 g KClO3:

when 245.2 g KClO3 gives → 96 g O2

     0.361 g KClO3 gives → X

∴ X = 0.361g KClO3 * 96 g / 245.2 g

       = 0.141 g of O2

C) 83.6 Kg KClO3:

when 245.2 g KClO3 gives → 96 g O2

       83.6 Kg KClO3 gives  →  X

∴X = 83.6 Kg* 96 g O2 /245.2 g KClO3

     = 32.7 Kg of O2

D) 22.4 mg of KClO3:

when 245.2 g KClO3 gives → 96 g O2

        22.4 mg KClO3 gives → X

∴X = 22.4 mg * 96 g O2 / 245.2 g KClO3

      = 8.8 mg of O2

     

 


7 0
3 years ago
Show the equation how many grams of Mg(OH)2 would be produced from 4 mol KOH?
Sindrei [870]
Mole ratio:

MgCl₂ + 2 KOH = Mg(OH)₂ + 2 KCl

2 moles KOH ---------------- 1 mole Mg(OH)₂
4 moles KOH ------------------- moles Mg(OH)₂

moles Mg(OH)₂   = 4 x 1 / 2

= 2  moles of   Mg(OH)₂

molar mass Mg(OH)₂ = 58g/mol

mass of   Mg(OH)₂ = n x mm

mass of  Mg(OH)₂ = 58 x  2

= 116 g of <span> Mg(OH)₂</span>

hope this helps!
8 0
3 years ago
The element chorine is represented by symbol ____. (Capitalization is important.)
liubo4ka [24]

the element chlorine is represented by the symbol Cl

6 0
3 years ago
Read 2 more answers
In multicellular organismscells that become specialized to perform a specific function are called?
Zolol [24]
The cell proliferates to produce many cells that result in multicellar organism.

answer
8 0
2 years ago
he Lewis structure for CO molecule contains Group of answer choices one double bond, one single bond, and twelve nonbonding elec
zimovet [89]

Answer:

One triple bond and four non bonding electrons

Explanation:

In considering the lewis structure of carbon monoxide, we must remember that the molecule contains a total of ten valence electrons. Four are the valence electrons that are present on the valence shell of carbon while six are the valence electrons on oxygen. Some of these valence electrons participate in bonding in the CO molecule.

Out of the six valence electrons on oxygen, two valence electrons participate in bonding with carbon while the other four electrons remain localized on the oxygen atom as two lone pairs of electrons.

Hence there are four nonbonding electrons in the lewis structure of CO as well as one triple bond.

6 0
3 years ago
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