CHEMISTRY HIGH SCHOOL

The reaction of Cr2O3 with silicon metal at high temperatures will make chromium metal.2Cr2​O3​(s)+3Si(s) -------> 4Cr(l)+3SiO2(s)

The reaction is begun with 161.00 g of Si and 139.00 g of Cr2O3.

How many grams of the excess reactant is left after the reaction is complete?

Answers

Answer 1
Answer:

Answer: 122.9 g of Si will be left from the given masses of both reactants.

Explanation:

2Cr_2O_3(s)+3Si(s)\rightarrow 4Cr(l)+3SiO_2(s)

To calculate the moles :

\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}    

\text{Moles of} Cr_2O_3=(139.00)/(152)=0.91moles

\text{Moles of} Si=(161.00)/(28)=5.75moles

According to stoichiometry :

2 moles of Cr_2O_3 require 3 moles of Si

Thus 0.91 moles of Cr_2O_3 will require=(3)/(2)* 0.91=1.36moles of Si

Thus Cr_2O_3 is the limiting reagent as it limits the formation of product and Si is the excess reagent.

Thus (5.75-1.36) = 4.39 moles  of excess reagent.

Mass of Si=moles* {\text {Molar mass}}=4.39moles* 28g/mol=122.9g

Thus 122.9 g of Si will be left from the given masses of both reactants.

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What is true of all mixtures?Group of answer choices

All mixtures are made up of 2 or more elements or compounds.

All mixtures are made up of solutions

All mixtures are made up of compounds.

All mixtures are made up of elements.

Answers

All mixtures are made up of two or more elements or compounds.

What are compounds?

Compound is defined as a chemical substance made up of identical molecules containing atoms from more than one type of chemical element.

Molecule consisting atoms of only one element is not called compound.It is transformed into new substances during chemical reactions. There are four major types of compounds depending on chemical bonding present in them.They are:

1)Molecular compounds where in atoms are joined by covalent bonds.

2) ionic compounds where atoms are joined by ionic bond.

3)Inter-metallic compounds where atoms are held by metallic bonds

4) co-ordination complexes where atoms are held by co-ordinate bonds.

They have a unique chemical structure held together by chemical bonds Compounds have different properties as those of elements because when a compound is formed the properties of the substance are totally altered.

Learn more about compounds,here:

brainly.com/question/13516179

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Answer:

Answer the first ine made up of 2 or more.....

The digestion process starts in the _____.esophagus
stomach
small intestine
mouth

Answers

Answer: mouth

Explanation:

The food digestion process in the human or animal body starts in the mouth. The mouth consists of teeth which helps in crushing and grinding of food. The mouth secretes saliva which provides lubrication to the food items. It helps in mixing process of the food so that it can be easily swallowed inside the gut and could enter into the digestive tract.

Your mouth is where the digestion process starts because when yo chew your food, nutrients is released into your body

How does an earthquake cause a tsunami?

Answers

yes because the earth plates are grinding against each other and are the main cause of Tsunami!
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Which of the following diagrams is the correct electron dot diagram for Ne?

Answers

Answer:

B.

Explanation:

The electron dot diagram which is also known as the Lewis electron dot diagram is a diagram that shows an atom's valence electrons by placing dots, which represent the valence electrons of the element, around the elements symbol

The element for which the electron dot diagram is found = Neon, Ne

The atomic number of neon, Ne = 10

The electronic configuration of neon = 1s²2s²2p⁶

The valence shell is the outermost shell having   the highest value of the coefficient of the orbitals, n = 2s²2p⁶

The number valence electrons in neon = The number of electrons in the valency shell = 2 electrons + 6 electrons = 8 electrons

The number of valence electrons in neon = 8

Therefore, the electron dot diagram for neon will have 8 dots located around the Ne symbol, which gives option B

6X, Y and Z are all gases that behave ideally and react according to the equation shown.
X(g) + 2Y(g) → 2Z(9)
When 3.0 mol of X and 3.0 mol of Y are placed inside a container with a volume of 1.0 dmº, they
react to form the maximum amount of Z.
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What is the final pressure inside the reaction vessel?
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D
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Answers

Answer:

D

Explanation:

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How many moles of NaCl are present in 23.5 grams of NaCl?

Answers

Answer:

0.342 mol

Explanation:

Molar mass of  

NaCl = 58.4 g/mol

Number of moles in  

20.0 g NaCl

is

20.0

g

58.4

g

/mol

=

0.342 mol
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