What is the molar mass of helium? (show your work)

When magnesium metal is heated in air it begins to release large amounts of heat and light. What kind of a reaction is this an e

Salsk061 [2.6K]

It is called exothermic reaction because it releases heat and light and it is called combustion reaction because it is reacting and is being oxidised by O2 to MgO. It can also be called as oxidation reaction since Mg is oxidised to MgO.

5 0

3 years ago

Read 2 more answers

The thermite reaction reacts iron (III) oxide, Fe2O3, with aluminium powder,Al, the form aluminium oxide, Al2O3 and iron, Fe.

lara [203]

Answer:

This answer assumes that the strated "16.0g of iron" was meant to be 16.0 grams of iron(III) oxide.

Explanation:

To start, the thermite equation must be balanced.

I find:

1Fe2O3 + 2Al = 1Al2O3 + 2Fe

This tells us we need 2 moles of Al for every 1 mole of Fe2O3.

Now calculate the moles of each reactant:

Moles Fe2O3: 16.0 g/159.7 g/mole = 0.100 moles Fe2O3

Moles Al: 8.1 /26.98 g/mole = 0.300 moles Al

The balanced equation says that in order to react all of the Fe2O3 we'd need twice that amount (in moles) of the Al. (0.100 moles Fe2O3)*(2) = 0.200 moles Al.

Which of the two reactants is the limiting reagent?

We have more than enough moles of Al to react with 0.10 moles of Fe2O3. (We have 0.300 moles Al and all we need is 0.200 moles to react with the 0.10 moles of Fe2O3. Fe2O3 is the limiting reagent.

Calculate the maximum mass of iron of iron that could be formed using these quantities of reactants.

The balanced equation tells us that we will obtain 2 moles of Fe for every 1 mole of Fe2O3 consumed. Since Fe2O3 is the limiting reagent, we will assume that it completely reacts. That means 0.1 moles of Fe2O3 is reacted. Since we expect twice that many moles of Fe, we should obtain 0.200 moles of Fe. At 55.85 g/mole, we should obtain:

(0.200 moles Fe)*(55.85 g Fe/mole Fe) = 11.2 grams Fe

5 0

1 year ago

The element born, b, has an atomic mass of 10.81 amu according to the periodic table. however, no single atom of boron has amass

klio [65]

The atomic mass or relative isotopic mass refers to the mass of a single particle, and therefore is tied to a certain specific isotope of an element. The dimensionless standard atomic weight instead refers to the AVERAGE of atomic mass values of a typical naturally-occurring mixture of isotopes for a sample of an element.
You can count it by yourself using formula

m = ({first isotopic distribution%}× {first atomic.mass})+ ({second isotopic distribution%}× {second atomic.mass}) / {100}

5 0

3 years ago

Which is true when a reaction has reached equalibrium

Serggg [28]

The answer should be: D. The reaction rate is equal in both directions

In the equilibrium state, the rate of reaction to the right is same as the reaction to the left. Because of this, the concentration of the reactant and product will be kept same.
It might seem like the reaction is stopped because there is no change in the concentration, but it wasn't. Adding a reactant or product will break the equilibrium state.

7 0

3 years ago

Imporance of mixture in our daily life

garri49 [273]

Answer:A mixture is a mechanical combination of several elements or compounds. Mixtures are used in cooking, chemical manufacturing, and a lot of other processes. A good mixture with the materials evenly distributed facilitates a good after mixture process. That might be a chemical reaction or a great cake. One mixture that we see the results of a lot is the mixture of water, gravel, and Portland cement that, after a good mix, becomes concrete. Other mixtures might include the various plastics and epoxies that require two or more parts to become a finished product. There are so many possible mixtures out there I’d suggest chemical engineering books , chemistry books in general, cook books, books on construction processes, and many other possible sources of mixtures and the results of using them.

Explanation:

4 0

3 years ago