How many atoms of Ca are in 1.65 mol of Ca?

What mass of S8 will completely react with 167.6 grams of Fe?

IRISSAK [1]

Answer:
mass of S₈ = 96.1146 grams

Explanation:
The balanced equation that describe the reaction is as follows:
8 Fe + S₈ ..............> 8 FeS

From the equation, we can note that:
8 moles of Fe react with 1 mole of S₈
This means that:
8 * 55.8 grams of iron react with 8 * 32 grams of S₈.
To know the mass of S₈ that will react with 167.6 grams of Fe, we will simply do cross multiplication as follows:
mass of S₈ = (167.6 * 8 * 32) / (8 * 55.8)
mass of S₈ = 96.1146 grams

Hope this helps :)

5 0

3 years ago

Three elements, A, Q, and Z, have the molar masses indicated in the table below. Given a compound with a composition of 15.66% A

Archy [21]

Answer:

AZ₂

Explanation:

The formed compound will not contain Q because mass percentages, %A and %B, form 100% of the compound.

Steps

Change % of each element into grams.
Convert grams of each element into moles by dividing grams by molar mass.
Divide all moles by the smallest number of moles.
If the moles are all whole numbers, then you’re done and that’s your empirical formula.
If not, multiply all moles by number such that everything is a whole number.

Solving

We have 15.66g of A and 84.34g of Z
Moles of A, n(A) = 15.66/15.45 = 1.01 moles
Moles of Z, n(Z) = 84.34/41.62 = 2.02 moles
A = 1.01/1.01 = 1 and Z = 2.02/1.01 = 2
Therefore, the empirical formula is AZ₂

8 0

2 years ago

How many moles of oxygen atoms are in 7.9E-1 moles of CO_2

Ilya [14]

Answer:

The number of moles of O atom in $(7.9\times10^{-1})$ mol of $CO_{2}$ = 1.6

Explanation:

1 molecule of $CO_{2}$ contains 2 atoms of O

So, $(6.023\times 10^{23})$ molecules of $CO_{2}$ contains $(2\times6.023\times10^{23})$ atoms of O.

We know that 1 mol of an atom/molecule/ion represents $6.023\times10^{23}$ numbers of atoms/molecules/ions respectively.

So, $(6.023\times 10^{23})$ molecules of $CO_{2}$ is equal to 1 mol of $CO_{2}$ .

$(2\times6.023\times10^{23})$ atoms of O is equal to 2 moles of O atom.

Hence, 1 mol of $CO_{2}$ contains 2 moles of O atom.

Therefore, $(7.9\times10^{-1})$ mol of $CO_{2}$ contains $(2\times7.9\times10^{-1})$ moles of O atom or 1.6 moles of O atom.

3 0

3 years ago

What is the mass of a piece of iron if it absorbs 5575 joules of heat and its specific heat capacity is 0.95 J/g°C? The initial

matrenka [14]

Answer:

The mass of iron piece = 586.84

Explanation:

Given,

Heat absorbed by iron piece(Q) = 5575 Joules.

specific heat capacity(Cp) = 0.95 J/g°C.

initial temperature(T₁) = 20.0°C

Final temperature(T₂) = 30.0°C

Mass of iron piece(m) = ?

The mass of iron piece can be calculated by using the formula ,

Q = (mass) (ΔT) (Cp)

Here, ΔT = T₂ - T₁ = 30°C - 20°C = 10°C

Substituting values we get,

5575 = (m)(10)(0.95)

Solving, we get,

m = 586.84 grams.

Therefore, mass of iron piece = 586.84 grams.

4 0

3 years ago

When magnesium reacts with chlorine, magnesium ions, Mg2+, and chloride ions, Cl−are formed. In this reaction, magnesium atoms A

Slav-nsk [51]

Answer: In the reaction, magnesium atoms lose electrons.

Explanation:

An ionic compound is defined as the compound which is formed when electron gets transferred from one atom to another atom. These are usually formed when a metal reacts with a non-metal or a metal reacts with a polyatomic ion or a reaction between two polyatomic ions takes place.

Magnesium is 12th element of the periodic table having electronic configuration of $1s^22s^22p^63s^2$

This element will loose 2 electrons to form $Mg^{2+}$ ion

Chlorine is 17th element of the periodic table having electronic configuration of $1s^22s^22p^63s^23p^5$

This element will gain 1 electron to form $Cl^-$ ion

By criss-cross method, the oxidation state of the ions gets exchanged and they form the subscripts of the other ions. This results in the formation of a neutral compound.

The ionic compound formed is $MgCl_2$

Hence, in the reaction, magnesium atoms lose electrons.

5 0

4 years ago