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3 years ago

How many grams of KCIO3 are needed to produce 5.00 of O2 at STP?

1 answer:

6 0

2KClO₃ → 2KCl + 3O₂

mole ratio of KClO₃ to O₂ is 2 : 3

∴ if moles of O₂ = 5 mol

then moles of KClO₃ = $\frac{5 mol * 2}{3}$

= 3.33 mol

Mass of KClO₃ needed = mol of KClO₃ × molar mass of KClO₃

= 3.33 mol × ((39 × 1) + (35.5 × 1) + (16 × 3) g/mol

= 407.93 g

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0.0200 M Fe3+ is initially mixed with 1.00 M oxalate ion, C2O42-, and they react according to the equation: Fe3+(aq) + 3 C2O42-(

Studentka2010 [4]

Answer : The concentration of $Fe^{3+}$ at equilibrium is 0 M.

Solution : Given,

Concentration of $Fe^{3+}$ = 0.0200 M

Concentration of $C_2O_4^{2-}$ = 1.00 M

The given equilibrium reaction is,

$Fe^{3+}(aq)+3C_2O_4^{2-}(aq)\rightleftharpoons [Fe(C_2O_4)_3]^{3-}(aq)$

Initially conc. 0.02 1.00 0

At eqm. (0.02-x) (1.00-3x) x

The expression of $K_c$ will be,

$K_c=\frac{[[Fe(C_2O_4)_3]^{3-}]}{[C_2O_4^{2-}]^3[Fe^{3+}]}$

$1.67\times 10^{20}=\frac{(x)^2}{(1.00-3x)^3\times (0.02-x)}$

By solving the term, we get:

$x=0.02M$

Concentration of $Fe^{3+}$ at equilibrium = 0.02 - x = 0.02 - 0.02 = 0 M

Therefore, the concentration of $Fe^{3+}$ at equilibrium is 0 M.

4 0

3 years ago

Is the reaction mg²⁺(aq) + h₂o(l) → mgo(s) + 2h⁺(aq) endothermic or exothermic?

aliya0001 [1]

<span>If energy is released, the reaction is exothermic. If energy is absorbed, the reaction is endothermic. Since heat is being absorbed in this reaction (to break down H2O into H2 and O), the reaction is endothermic.</span>

3 0

3 years ago

Which scientist arranged the elements in order of increasing atomic number, rather than increasing atomic mass?

pentagon [3]

Answer:

Henry Moseley

Explanation:

Dmitry Mendeleef and Lothar Meyer proposed a periodic table based on the atomic mass.

They stated a periodic law expressed as "chemical properties of elements are a periodic function of their atomic weights".

But, Henry Moseley in 1900s re-stated periodic law by changing the basis of the law from atomic weight to atomic number.

The present periodic law is stated as "the properties of elements are a periodic function of their atomic number".

6 0

3 years ago

How many moles of mgs2o3 are in 193 g of the compound?

Mashutka [201]

Answer:

1.414 Moles

Solution:

Data Given:

Mass of MgS₂O₃ = 193 g

M.Mass of MgS₂O₃ = 136.43 g.mol⁻¹

Moles = ?

Formula Used:

Moles = Mass ÷ M.Mass

Putting values,

Moles = 193 g ÷ 136.43 g.mol⁻¹

Moles = 1.414 mol

8 0

3 years ago

When electrolyzing copper (ll) chloride, what reaction takes place at the anode? What reaction takes place at the cathode?

klemol [59]

Answer:

Copper ions are reduced into copper atoms.

Cu²⁺₍aq₎ + 2e⁻ → Cu₍s₎

Explanation:

During electrolysis, the positive H⁺ and Cu⁺ ions move to the negative cathode and negative OH⁻ and Cl⁻ ions move to the positive anode.

At cathode, copper ions are preferentially discharged due to the low electromotive force required to discharge them compared to the hydrogen ion. The copper ions gain the two electrons lost by the chloride ions when the are discharged. (2 Cl⁻₍aq₎ → Cl₂₍g₎ + 2e⁻)

Thus the half equation is as follows:

Cu²⁺₍aq₎ + 2e⁻ → Cu₍s₎

5 0

3 years ago