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3 years ago

How many formula units make up 15.0 g of magnesium chloride (MgCl2)?

1 answer:

8 0

The formula mass of MgCl - atomic mass of Mg + 2(atomic mass of Cl)
formula mass - 24.3 + (35.45x2) = 95.2
In 95.2 of MgCl₂ - there are 6.022 x 10²³ formula units of MgCl₂
Therefore in 15.0 g of MgCl2 - there are 6.022 x 10²³ /95.2 x 15.0 = 9.49 x 10²² formula units of MgCl₂
the number of formula units - 9.49 x 10²² formula units of MgCl₂

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Calculate the mass of 3.05 buckets of golf balls.

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3 years ago

What mass of CO2 in grams will form 8.94 g O2 completely react?

VLD [36.1K]

Through ratio and proportion, for every mole of O2, there is also a mole equivalent of CO2. In this case, we divide first 8.94 g O2 by 32 g/mol to convert the mass to mole. That is equivalent to 0.279375 mol which is also the amount of CO2. Multiplied by 44g/mol which is the molar mass of CO2, the answer is 12.29 grams CO2.

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3 years ago

What is the amount of heat required to complete MELT a 200 gram sample of H2O(s)

wolverine [178]

Answer:

66800 J

Explanation:

From the question given above, the following data were obtained:

Mass (m) = 200 g

Heat (Q) required =?

The heat required to melt the 200 g sample of water can be obtained as:

Mass (m) = 200 g

Latent heat of water (L) = 334 J/g

Heat (Q) required =?

Q = mL

Q = 200 × 334

Q = 66800 J

Thus, 66800 J of heat energy is required to melt the sample of water.

8 0

2 years ago

Read 2 more answers

2.3 Zinc has five naturally occurring isotopes: 48.63% of 64 Zn with an atomic weight of 63.929 amu; 27.90% of 66Zn with an atom

lakkis [162]

Answer: The average atomic mass of element Zinc is 65.40 amu.

Explanation:

Average atomic mass of an element is defined as the sum of masses of each isotope each multiplied by their natural fractional abundance.

Formula used to calculate average atomic mass follows:

$\text{Average atomic mass }=\sum_{i=1}^n\text{(Atomic mass of an isotopes)}_i\times \text{(Fractional abundance})_i$ .....(1)

For $_{30}^{64}\textrm{Zn}$ isotope:

Mass of $_{30}^{64}\textrm{Zn}$ isotope = 63.929 amu

Percentage abundance of $_{30}^{64}\textrm{Zn}$ isotope = 48.63 %

Fractional abundance of $_{30}^{64}\textrm{Zn}$ isotope = 0.4863

For $_{30}^{66}\textrm{Zn}$ isotope:

Mass of $_{30}^{66}\textrm{Zn}$ isotope = 65.926 amu

Percentage abundance of $_{30}^{66}\textrm{Zn}$ isotope = 27.90 %

Fractional abundance of $_{30}^{66}\textrm{Zn}$ isotope = 0.2790

For $_{30}^{67}\textrm{Zn}$ isotope:

Mass of $_{30}^{67}\textrm{Zn}$ isotope = 66.927 amu

Percentage abundance of $_{30}^{67}\textrm{Zn}$ isotope = 4.10 %

Fractional abundance of $_{30}^{67}\textrm{Zn}$ isotope = 0.0410

For $_{30}^{68}\textrm{Zn}$ isotope:

Mass of $_{30}^{68}\textrm{Zn}$ isotope = 67.925 amu

Percentage abundance of $_{30}^{68}\textrm{Zn}$ isotope = 18.75 %

Fractional abundance of $_{30}^{68}\textrm{Zn}$ isotope = 0.1875

For $_{30}^{70}\textrm{Zn}$ isotope:

Mass of $_{30}^{70}\textrm{Zn}$ isotope = 69.925 amu

Percentage abundance of $_{30}^{70}\textrm{Zn}$ isotope = 0.62 %

Fractional abundance of $_{30}^{70}\textrm{Zn}$ isotope = 0.0062

Putting values in equation 1, we get:

$\text{Average atomic mass of Zinc}=[(63.929\times 0.4863)+(65.926\times 0.2790)+(66.927\times 0.0410)+(67.925\times 0.1875)+(69.925\times 0.0062)]$

$\text{Average atomic mass of Zinc}=65.40amu$

Hence, the average atomic mass of element Zinc is 65.40 amu.

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3 years ago

Select the correct answer.

Artist 52 [7]

I think c cause if he is in a relationship that’s abusive he needs to speak up before it goes way worst.

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3 years ago