.How many grams of NaCl required to form a 500ml solution with a molarity of 0.5M , the molar mass of NaCl is 58.5g/mol?

Answer is: empirical formula is Fe₂O₃.
m(Fe) = 7,50 g.
m(iron oxide) = 10,71 g.
n(Fe) = m(Fe) ÷ M(Fe).
n(Fe) = 7,50 g ÷ 55,85 g/mol = 0,134 mol.
m(O) = m(iron oxide) - m(Fe).
m(O) = 10,71 g - 7,50 g = 3,21 g.
n(O) = 3,21 g ÷ 16 g/mol = 0,20 mol.
n(Fe) : n(O) = 0,134 mol : 0,2 mol = 2 : 3.

3 0

4 years ago

Solve: Turn off Show summary. Use the Choose reaction drop down menu to see other equations, and balance them. Check your answer

suter [353]

Answer: See below

Explanation:

To balance equations, you want to have the same amount of elements on the product and reactants side.

__Al+ __HCl→__AlCl₃+ __H₂

We see that there are 3 Cl on the products side and 1 on the reactants side, but there are 2 H on the product and 1 on reactant. To fulfill them both, let's put a 6 at HCl.

__Al+ 6HCl→__AlCl₃+ __H₂

Now that we have a 6 at HCl, we can fill in AlCl₃ and H₂.

__Al+ 6HCl→ 2AlCl₃+ 3H₂

All we have left is to fill in Al.

2Al+ 6HCl→ 2AlCl₃+ 3H₂

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__NaCl→ __Na+ __Cl₂

Since we have 2 Cl on the products, we must put 2 on the reactants.

2NaCl→ __Na+ 1Cl₂

With 2 NaCl, we can fill in Na.

2NaCl→ 2Na+ 1Cl₂

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__Na₂S+ __HCl→ __NaCl+ __H₂S

We see 2 Na on reactants, so we can put 2 on the products.

__Na₂S+ __HCl→ 2NaCl+ __H₂S

With 2 H and 2 Cl on the products, we can put a 2 at HCl.

1Na₂S+ 2HCl→ 2NaCl+ 1H₂S

7 0

3 years ago

Ana amount of nitrogen undergoes a physical change and increases its volume. What can be known about this physical change

Natali [406]

Answer:

D.) the density changed

Explanation:

This would be the answer because it is a specific amount of Nitrogen undergoing a physical change. Since the color and boiling point don't influence a change in volume, those are ruled out. Also, nitrogen's molecular mass never changes, so that would not make sense either. But if the density, which is mass/volume, has changed (more specifically decreases) then it means the volume has increased.

Hope this helps.

6 0

3 years ago

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