Someone plz plz answer this hurry plz it

A sample of pure calcium fluoride with a mass of 15.0 g contains 7.70 g of calcium. how much calcium is contained in 45.0 g of c

kolbaska11 [484]

In a sample of pure calcium fluoride of mass 15.0 g, 7.70 g of calcium is present. First convert the mass into number of moles as follows:

$n=\frac{m}{M}$

Here, m is mass and M is molar mass.

Molar mass of Ca is 40 g/mol, putting the values,

$n=\frac{7.70 g}{40 g/mol}=0.1925 mol$

Similarly, molar mass of $CaF_{2}$ is 78.07 g/mol thus, number of moles will be:

$n=\frac{15.0 g}{78.07 g/mol}=0.1921 mol$ .

Thus, 0.1921 mol of $CaF_{2}$ have 0.1925 mol of Ca, or 1 mole of $CaF_{2}$ will have approximately 1 mole of Ca.

Now, mass of Ca needs to be calculated in 45.0 g of $CaF_{2}$ . Converting mass into number of moles first,

$n=\frac{45.0 g}{78.07 g/mol}=0.5764 mol$

Thus, number of moles of Ca will also be 0.5764 mol, converting number of moles into mass,

$m=n\times M=0.5764 mol\times 40 g/mol=23.06 g$

Therefore, mass of Ca will be 23.06 g.

6 0

3 years ago

2. If you have 8.08 g of hydrogen, how many grams of ammonia will your produce?

Nikolay [14]

answer: Stoichiometry is a big word for a process that chemist’s use to calculate

amounts in reactions. It makes use of the coefficient ratio set up by balanced

reaction equations to make connections between the reactants and products

in reactions.

 Stoichiometry calculates the quantities of reactants and products in a

chemical reaction. The equation must be balanced!

 Questions that deal with amounts in reactions are examples of reaction

stoichiometry. We already have the tools necessary to solve this question.

We just need to learn a new way to apply skills such as writing chemical

formulas, calculating formula masses, and converting from mass to moles,

particles to moles, and volume of gases to moles.

 Mole to Mole Conversions- you must have the Mole Ratio.

Illustration:

Let’s use an analogy that we can understand to begin to understand the process.

The KEY to any mole conversion is the ratio of coefficients in the reaction

equation. Say I want to make a bacon double cheeseburger. Let’s get our recipe

together.

1 hamburger bun + 2 hamburger patties + 2 slices of cheese + 4 strips of bacon →

1 bacon double cheeseburger

Based on this recipe:

1) If I have five bacon double cheeseburgers:

a. How many hamburger buns did you use? → 5 hamburger bun

b. How many hamburger patties did you use? → 10 hamburger patties

c. How many slices of cheese did you use? → 10 slices of cheese

d. How many strips of bacon did you use? → 20 strips of bacon

2) How many bacon double cheeseburgers can you make if you start with:

a. 2 buns, 4 patties, 4 slices of cheese, 8 strips of bacon

2 bacon double cheese burgers

b. 1 dozen buns, 2 dozen patties, 2 dozen slices of cheese, 4 dozen strips of bacon

1 dozen bacon double cheese burgers

7 0

2 years ago

What is the correct formula for Elementium Nitride?

sashaice [31]

Answer:

AlN

Explanation:

have a great day

7 0

2 years ago

Rank the following molecules from highest to lowest boiling point: CO2, H2S, NaF, NH3. Explain your ranking using IMF’s.

qaws [65]

Answer:

NaF>NH3>H2S>CO2

Explanation:

The boiling point of a substance depends on the magnitude of electronegativity difference and the type of bond between the atoms of the compound in question.

NaF is an ionic substance. Ionic substances have a high melting and boiling point due to the fact that the ionic lattice contains a large number of ions. This means that a lot of energy is usually required to overcome this ion-ion interaction therefore ionic compounds usually have high melting and boiling points.

Nitrogen is more electronegative than sulphur hence NH3 is more polar than H2S and consequently NH3 has a higher boiling point than H2S due to stronger dipole-dipole interaction.

CO2 is a nonpolar molecule hence it has the lowest boiling point. Only weak dispersion forces exist in CO2.

8 0

3 years ago

Draw a reaction energy profile (energy vs dihedral angle) for rotation about the c-c bond in ethane. Show the Newman projections

astraxan [27]

Answer:

The energy profile for rotation about the C-C bond in ethane is shown in the image, along with the Newman projections of the corresponding ethane conformer.

Explanation:

If you see the ethane molecule (second image) from the C-C bond axis (third image), as in the Newman projections, it's easy to draw an angle between one of the hydrogen atoms of the visible carbon, the carbon itself, and one of the hydrogens of the hidden carbon.

When you make a rotation about the C-C bond, the angle between those hydrogens will change. If you start with an eclipsed conformation, with each hydrogen of the hidden C exactly behind the hydrogens of the visible C, the angle will be 0°, or also 120° or 240°, as this rotations will be equivalent. On the other hand, if the angle is 60° (or 180°, or 300°), you will have a staggered conformation. The eclipsed conformation is less stable than the staggered one, because the interactions between hydrogens will be bigger (the repulsion between their electrons), and because of that the eclipsed conformations will be found in the maxima, while the staggered one will be found in the minima.

8 0

2 years ago