You have a particle of length 68 nm. What is this in meters? ( need help asap)

Water is heated to boiling and water vapor (steam) is released. Chemical change or physical change?

Vlad [161]

Physical because it is still H2O

6 0

2 years ago

from the following equation in which decomposition of CaCO3 takes place, give your justification. CaCO3 gives Ca +CO2

IceJOKER [234]

Answer:

CaCO₃(s) => CaO(s) + CO₂(g) ... GpIIA Decomp

Explanation:

Metallic Carbonates decompose into a metallic oxide and carbon dioxide.

Examples:

Na₂CO₃(s) => Na₂O(s) + CO₂(g) ... GpIA Decomp

MgCO₃(s) => MgO(s) + CO₂(g) ... GpIIA Decomp

7 0

2 years ago

How many electrons are there in carbonate ion, CO3^-2?

NISA [10]

It should be 24 electrons

3 0

2 years ago

When 125 grams of FeO react with 25.0 grams of Al, how many grams of Fe can be produced? FeO + Al → Fe + Al2O3 25.9 g Fe 38.7 g

Serga [27]

Answer: The mass of iron produced will be 77.6 grams

Explanation:

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$ .....(1)

For FeO:

Given mass of FeO = 125 g

Molar mass of FeO = 71.8 g/mol

Putting values in equation 1, we get:

$\text{Moles of FeO}=\frac{125g}{71.8g/mol}=1.74mol$

For aluminium:

Given mass of aluminium = 25.0 g

Molar mass of aluminium = 27 g/mol

Putting values in equation 1, we get:

$\text{Moles of aluminium}=\frac{25.0g}{27g/mol}=0.93mol$

The given chemical reaction follows:

$3FeO+2Al\rightarrow 3Fe+Al_2O_3$

By Stoichiometry of the reaction:

2 moles of aluminium metal reacts with 3 mole of FeO

So, 0.93 moles of aluminium metal will react with = $\frac{3}{2}\times 0.93=1.395mol$ of FeO

As, given amount of FeO is more than the required amount. So, it is considered as an excess reagent.

Thus, aluminium metal is considered as a limiting reagent because it limits the formation of product.

By Stoichiometry of the reaction:

2 moles of aluminium metal produces 3 mole of iron metal

So, 0.93 moles of aluminium metal will produce = $\frac{3}{2}\times 0.93=1.395moles$ of iron metal

Now, calculating the mass of iron metal from equation 1, we get:

Molar mass of iron = 55.85 g/mol

Moles of iron = 1.395 moles

Putting values in equation 1, we get:

$1.395mol=\frac{\text{Mass of iron}}{55.85g/mol}\\\\\text{Mass of iron}=(1.395mol\times 55.85g/mol)=77.6g$

Hence, the mass of iron produced will be 77.6 grams

4 0

2 years ago

A chocolate bar weighs 4.00 ounces. If the chocolate delivers 2.78 calories per gram, how many

dimulka [17.4K]

Answer:

40.79

Explanation:

an ounce is equal to approximately 28.3 grams.

if you have 4 ounces then it would be equal to about 113.4 grams. then you would divide that by 2.78 which will equal about 40.8

6 0

2 years ago