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3 years ago

What is the formula for manganese (ii) fluoride decahydrate? (you may use a * to represent the dot in the formula.)?

2 answers:

4 0

These types of molecules are called hydrates. They have a certain number of moles attached to the salt. Their characteristic is being hygroscopic. That means that when they are exposed to air, they readily solvate.

The formula for Manganese Fluoride Decahydrate will involve the formula Mn, F and H₂O. In ionic form, Manganese is Mn⁺² while fluoride is in F⁻. When they are brought together, their superscripts are 'cross-multiplied' and becomes their respective subscripts. The compound becomes MnF₂. Then, we add the decahydrate which means 10 moles of H₂O. Hence, the formula for Manganese Fluoride Decahydrate is MnF₂*10H₂O.

goblinko [34]3 years ago

3 0

Answer:

MnF₂*10H₂O.

Explanation:

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A sample of CaCO3(s) is introduced into a sealed container of volume 0.638 L and heated to 1000 K until equilibrium is reached.

JulsSmile [24]

Answer:

the mass of CaO present at equilibrium is, 0.01652g

Explanation:

$K_p = [CO_2]$ = 3.8×10⁻²

Now we have to calculate the moles of CO₂

Using ideal gas equation,

PV =nRT

P = pressure of gas = 3.8×10⁻²

T = temperature of gas = 1000 K

V = volume of gas = 0.638 L

n = number of moles of gas = ?

R = gas constant = 0.0821 L.atm/mole.k

$\frac{3.8 * 10^2 * 0.638}{0.0821 * 1000} \\= 2.95 * 10^-^4$

Now we have to calculate the mass of CaO

mass = 2.95 * 10 ⁻⁴ × 56

= 0.01652g

Therefore,

the mass of CaO present at equilibrium is, 0.01652g

7 0

3 years ago

SYNTHESIS OFCARBONATECTIONLABORATORY SIMULATIONLab Data- X99.00.10CollectedVolume sodium carbonate (mL)Molarity sodium carbonate

evablogger [386]

Answer:

$\begin{gathered} \text{Limiting Reagent = Sodium Carbonate} \\ \text{Percent Yield = 98\%} \end{gathered}$

Explanation:

The chemical reaction talks about the synthesis of calcium carbonate

It is from the reaction between sodium carbonate and calcium chloride

Let us write the equation of reaction as follows:

$Na_2CO_{3(aq)}+CaCl_{2(aq)}\text{ }\rightarrow2NaCl_{(s)\text{ }}+CaCO_{3(aq)}$

Firstly, we want to get the expected mass of calcium carbonate

This speaks about getting the theoretical yield based on the equation of reaction

From the data collected, 90 ml of 0.20 M (mol/L) of sodium carbonate gave calcium carbonate

We need to get the actual number of moles of sodium carbonate that reacted

We can get this by multiplying the volume by the molarity (kindly note that we have to convert the volume to Liters by dividing by 1000)

Thus, we have it as:

$\frac{90}{1000}\times\text{ 0.1 = 0.009 moles}$

Hence, we see that 0.009 moles of sodium carbonate reacted theoretically

Since 1 mole of sodium carbonate gave 1 mole calcium carbonate, it is expected that 0.009 mole of sodium carbonate will give 0.009mole of calcium carbonate

What we have to do now is to get the theoretical grams of calcium carbonate produced

That would be the product of the number of moles of calcium carbonate and its molar mass

The molar mass of calcium carbonate is 100 g/mol

The theoretical yield (expected mass) is thus:

$100\text{ g/ mol }\times\text{ 0.009mol = 0.9 g}$

Finally, we proceed to get the percentage yield which is calculated using the formula below:

$\text{Percent Yield = }\frac{Actual\text{ yield}}{\text{Theoretical yield}}\times\text{ 100 \%}$

The actual yield is the observed mass which is given as 0.88 g

The percent yield is thus:

$\frac{0.88}{0.9}\times\text{ 100 = }98\text{ \%}$

7 0

1 year ago

Which statement best describes waves? A.Waves can only travel in empty space B.Waves cannot propagate without medium C.Waves can

avanturin [10]

The statement that best describes waves is B. Waves cannot propagate without a medium

6 0

3 years ago

Read 2 more answers

The initial reaction rate for the elementary reaction 2A + B → 4C was measured as a function of temperature when the concentrati

Artist 52 [7]

Complete Question

The complete question is shown on the first uploaded image

Answer:

a) The activation energy is 124.776 $\frac{kJ}{mole}$

b) The frequency factor is 1.77 × $10^{18}$

c) The rate constant is 0.00033 $(\frac{dm^{3} }{mole} )^{2}$ $\frac{1}{s}$

Explanation:

From the question the elementary reaction for A and B is given as

2A + B → 4C

The rate equation the elementary reaction is

- $r_{A}$ = $k$ $[A]^{2}$ $[B]$

= $k[2]^{2}[1.5]$

= 6k

$k = \frac{-r_{A} }{6}$

When temperature changes, the rate constant change an this causes the rate of reaction to change as shown on the second uploaded image.

The relationship between temperature and rate constant can be deduced from these equation

$k = Aexp(-\frac{E_{a} }{RT} )$

taking ln of both sides we have

$lnk =ln A - (\frac{E_{a} }{R}) \frac{1}{T}$

Considering the graph for the rate constant $ln k$ and $(\frac{1}{T} )$ the slope from the equation is $-(\frac{E_{a} }{R})$ and the intercept is $ln A$

From the given table we can generate another table using the equation above as shown on the third uploaded image

The graph of $ln k$ vs $(\frac{1}{T} )$ is shown on the fourth uploaded image

From the graph we can see that the slope is $-(\frac{E_{a} }{R} ) = - 15008$

Now we can obtain the activation energy $E_{a}$ by making it the subject in the equation also generally R which is the gas constant is $8.145 \frac{J}{kmole}$

$E_{a} = 15008 × 8,3145\frac{J}{molK}$

$= 124\frac{KJ}{mole}$

Hence the activation energy is $= 124\frac{KJ}{mole}$

b) From the graph its intercept is $ln A = 42.019$

$A = exp(42.019)$

$=1.77 × 10^{18}$

Hence the frquency factor A is $=1.77 × 10^{18}$

c) From the equation of rate constant

$lnk =ln A - (\frac{E_{a} }{R}) \frac{1}{T}$

We have

$ln k = 42.019 - 15008 * (\frac{1}{300} )$

$k = 0.00033(\frac{dm^{3} }{mole} )^{2} \frac{1}{s}$

Hence the rate constant is $k = 0.00033(\frac{dm^{3} }{mole} )^{2} \frac{1}{s}$

6 0

3 years ago

The atomic mass of an element on the Periodic Table is the weighted average mass of the isotopes of that element. True False

Gala2k [10]

True!

For example:

The atomic mass of carbon is 12.011 (i think) and the weight of carbon is 12. But with C13 and C14 being a little higher, it makes the average higher. Random fact: C14 is used for carbon dating.

3 0

3 years ago