Why does the moon appear to move across the sky

Consider the following data for five hypothetical elements: Q, W, X, Y, and Z. Rank the elements from most reactive to least rea

aleksley [76]

Answer:

Y Q W Z X

Explanations:

The most reactive element is the element that will displace an element from it compound . The most reactive element will replace the less reactive element in it compound.

Q+ + Y Reaction occurs

Since the reaction occurs the element Y which is more reactive displaced element Q from it compound.

Q+W+ Reaction occurs

The reaction occurs, that means element Q replaces element w from it compound. Element Q is therefore more reactive than element W.

W+Z+ Reaction occurs

The reaction also occurs . This is an indication that element W replaces element Z in it compound. This means element W is very reactive than element Z.

X+Z+ No reaction

There is no reaction here. This is an indication that element X is less reactive than element Z. This is why element X can't displace element Y in it compound.

4 0

3 years ago

Differentiate between short period and long period in modern periodic table

AfilCa [17]

The difference between short period and long period is based upon the number of elements in each period. Shortest period is the first period which contains elements, while the longest period is the 6th period which contains 32 elements.

8 0

3 years ago

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If 125g of KClO3 is heated, what is the total mass of the products?

Andrej [43]

Given parameters:

Mass of KClO₃ = 125g

Unknown:

Total mass of the products = ?

When KClO₃ is heated, it thermally decomposes to KCl and O₂ according to the chemical equation below;

2KClO₃ → 2KCl + 3O₂

All chemical equations obeys the law of conservation of matter and with this regard, we know that the amount of reactants used is the same as that of the product.

The total mass of the products must give us 125g according to this law of conservation of matter.

Now to find the masses of each product,

Find the number of moles of the given reactant:

Number of moles = $\frac{mass}{molar mass}$

molar mass of KClO₃ = 39 + 35.5 + 3(16) = 122.5g/mol

So number of moles of KClO₃ = $\frac{125}{122.5}$ = 1.02moles

2. Now, using this number of moles, find the number of moles of the products using this value;

2 moles of KClO₃ produced 2 moles of KCl

1.02 moles of KClO₃ will also produce 1.02moles of KCl

2 moles of KClO₃ produced 3 moles of O₂

1.02 moles of KClO₃ will produce $\frac{1.02 x 3} {2}$ mole = 1.53 moles of O₂

3. Now find the masses of each product;

Mass = number of moles x molar mass

molar mass of KCl = 39 + 35.5 = 74.5g/mol

molar mass of O₂ = 16 x 2 = 32g/mol

Mass of KCl = 74.5 x 1.02 = 75.99g

Mass of O₂ = 32 x 1.53 = 48.96g

Total mass of products = mass of KCl + Mass of O₂ = 75.99g + 48.96g

= 124.95g

This value is approximately the same as that of mass of KClO₃

7 0

3 years ago

What mass of iron is formed when 10 grams of carbon react with 80 grams of iron iii oxide?

yKpoI14uk [10]

Answer:

55.85 grams of Fe is formed.

Explanation:

Identify the reaction:

2Fe₂O₃ + 3C → 4Fe + 3CO₂

Identify the limiting reactant, previously determine the mol of each reactant

(mass / molar mass)

10 g / 12 g/m = 0.83 moles C

80 g / 159.7 g /m = 0.500 moles Fe₂O₃

2 moles of oxide need 3 moles of C, to react

0.5 moles of oxide, will need ( 0.5 . 3)/ 2 = 0.751 mol

I have 0.83 moles of C, so C is the excess.

The limiting is the oxide.

3 mol of C need 2 mol of oxide to react

0.83 mol of C, will need (0.83 . 2)/ 3 = 0.553 mol of oxide, and I only have 0.5 (That's why Fe₂O₃ is the limiting)

Ratio is 2:4 (double)

If I have 0.5 moles of oxide, I will produce the double, in the reaction.

1 mol of Fe, will be produce so its mass is 55.85 g

5 0

3 years ago

MY NOTES ASK YOUR TEACHER Consider a different titrant for this exercise. Suppose Ca(OH)2 were used as the titrant, instead of N

Alekssandra [29.7K]

Answer:

Two moles of HC2H3O2 react with one mole of Ca(OH)2 to produce one mole of calcium acetate and two moles of water.

Explanation:

HC2H3O2 is Acetic acid that can also be represented as (CH3COOH).

when Ca(OH)2 reacts with Acetic acid the product formed will be Calcium acetate and water

Chemically the reaction can be represented as

2CH 3 COOH + Ca(OH) 2 → Ca(CH 3 COO) 2 + 2H 2 O

Two moles of CH3COOH react with one mole of Ca(OH)2 to produce one mole of Ca(CH3COO)2 and two moles of H2O.

7 0

3 years ago