What is the matter of science

If 10.0g of powdered iron is heated with 10.0g of sulfur in an open crucible, what is the mass of iron (II) sulfide that is form

Ugo [173]

Answer:

See Explanation

Explanation:

8Fe + S₈ => 8FeS

Given: 10g 10g

moles 10g/56g/mol 10g/256g/mol

= 0.179mol Fe = 0.039mol S₈

Reduce => divide mole values by respective coefficients; smaller value is Limiting Reactant.

0.179/8 = 0.022 0.039/1 = 0.039

=> Fe is limiting reactant

8Fe + S₈ => 8FeS

Given: 10g/56g/mol 10g/256g/mol

= 0.179mol = 0.039 mol 0.179mol FeS produced

1/8(0.179)mol S₈ used (coefficients are equal,

= 0.022 mol S₈ used => moles Fe = moles FeS)

= (0.039 - 0.022)mol S₈ = 0.179mol FeS

remains in excess =(0.179mol)(88g/mol)

= 0.0166 mol S₈ (excess) = 15.8 g FeS

= (0.0166mol)(256g/mol) (Theoretical Yield)

= 4.26g S₈ in excess

7 0

3 years ago

A 1.0 L buffer solution is 0.300 M HC2H3O2 and 0.045 M LiC2H3O2. Which of the following actions will destroy the buffer?

zheka24 [161]

Answer:

b) Adding 0.075 moles of HCl

Explanation:

A buffer is defined as the aqueous mixture of a weak acid and its conjugate base or vice versa (Weak base with its conjugate acid).

The buffer of the problem is the acetic acid / lithium acetate.

The addition of any moles of the acid and the conjugate base will not destroy the buffer, just would change the pH of the buffer. Thus, a and c will not destroy the buffer.

The addition of an acid (HCl) or a base (NaOH), produce the following reactions:

HCl + LiC₂H₃O₂ → HC₂H₃O₂ + LiCl

The acid reacts with the conjugate base to produce the weak acid.

And:

NaOH + HC₂H₃O₂ →NaC₂H₃O₂ + H₂O

The base reacts with the weak acid to produce conjugate base.

As the buffer is 1.0L, the moles of the species of the buffer are:

HC₂H₃O₂ = 0.300 moles

LiC₂H₃O₂ = 0.045 moles

The reaction of HCl with LiC₂H₃O₂ consume all LiC₂H₃O₂ -because there are an excess of moles of HCl that react with all LiC₂H₃O₂-

As you will have just HC₂H₃O₂ after the reaction, the addition of b destroy the buffer.

In the other way, 0.0500 moles of NaOH react with the HC₂H₃O₂ but not consuming all HC₂H₃O₂, thus d doesn't destroy the buffer.

5 0

3 years ago

Which is a property of a mineral A. Size B. Density C. Odor D. Age

ollegr [7]

B. density is the right answer

3 0

3 years ago

Which action is an example of an organism maintaining homeostatis

VLD [36.1K]

Answer:

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The body regulates those levels in an example of homeostasis. When levels decrease, the parathyroid releases hormones. If calcium levels become too high, the thyroid helps out by fixing calcium in the bones and lowering blood calcium levels. The nervous system helps keep homeostasis in breathing patterns.

7 0

3 years ago

The half-life of gold-198 is 2.7 days. After

Pie

Answer: 8.1 days

Explanation:

Expression for rate law for first order kinetics is given by:

$t=\frac{2.303}{k}\log\frac{a}{a-x}$