What occurs during a decomposition reaction

What are four indications that a chemical reaction bay be taking place

Mariana [72]

When a chemical reaction takes place it changes the composition of the reactants. The ways to tell if a reaction is occurring are,
1-Release of heat
2-Production of a gas
3-Formation of a precipitate
4-Change in color

3 0

3 years ago

For each chemical equation below, write the number of product molecules that will form from the reaction.

Gekata [30.6K]

Answer:

a. 5 moles of CO₂

b. 2 moles of NaCl

c. 3 moles of H₂CO₃

Explanation:

1a. Carbon reacts with oxygen to produce carbon dioxide according to equation below:

C + O₂ ----> CO₂

From the equation of reaction, one mole of carbon reacts with one mole of oxygen to produce one mole of carbon dioxide.

In the given reaction, therefore, 5 moles of carbon will only react with 5 moles of oxygen to produce 5 moles of carbon dioxide. Oxygen is in excess, carbon is the limiting reactant and 5 moles of carbon dioxide are produced. The equation is given below :

5 C + 6 O₂ ---> 5 CO₂

1b. Sodium reacts with chlorine to produce sodium chloride according to the equation below:

2 Na + Cl₂ ---> NaCl

From the equation of reaction, 2 moles of sodium reacts with one mole of chlorine to produce one mole of sodium chloride.

In the given reaction, therefore, 4 moles of sodium will react with only 2 moles of chlorine to produce 2 moles of sodium chloride. Chlorine is in excess, sodium is the limiting reactant and 2 moles of sodium chloride are produced. The equation is given as follows: 4 Na + 8 Cl₂ ---> 2 NaCl

1c. Carbon dioxide reacts with water to produce carbonic acid according to the equation: CO₂ + H₂O ---> H₂CO₃

From the equation of reaction one mole of carbon dioxide reacts with one mole of water to produce one mole of carbonic acid.

In the given reaction, therefore, 3 moles of carbon dioxide will react with only 3 moles of water to produce 3 moles of carbonic acid. Water is in excess, carbon dioxide is the limiting reactant and 3 moles of carbonic acid are produced. The equation is given as follows: 3 CO₂ + 4 H₂O ---> 3 H₂CO₃

4 0

3 years ago

A reaction between liquid reactants takes place at −10.0°C in a sealed, evacuated vessel with a measured volume of 45.0L. Measur

maks197457 [2]

Answer: 0.0624 atm

Explanation:-

According to the ideal gas equation:

$PV=nRT$

P = Pressure of the gas = ?

V= Volume of the gas = 45.0 L

T= Temperature of the gas = -10.0°C = 263 K $0^00C=273K$

R= Gas constant = 0.0821 atmL/K mol

n= moles of gas

Moles of gas= $\frac{\text{ given mass}}{\text{ molar mass}}= \frac{19.0g}{146g/mole}=0.130moles$

$P=\frac{nRT}{V}=\frac{0.130\times 0.0821\times 263}{45.0}=0.0624atm$

The pressure of sulfur hexafluoride gas in the reaction vessel after the reaction is 0.0624 atm

3 0

3 years ago

What is the limiting reactant in a chemical reaction?

IgorC [24]

Answer:

D.) the reactants that runs out first

Explanation:

Limiting reactant is the reactant which is present in the smallest amount and thus limit the yield of product.

In any chemical reaction limiting reactant is identified by steps:

First we will calculate the number of moles of given amount of reactants.

Then we will find the number of moles of product by comparing with moles of reactant through balanced chemical equation.

Then we will identified the reactant which produced smaller amount of product.

It can be better understand by following problem.

Given data:

Mass of calcium carbonate = 25 g

Mass of hydrochloric acid = 13.0 g

Mass of calcium chloride produced = ?

Which is limiting reactant= ?

Chemical equation:

CaCO₃ + 2HCl → CaCl₂ + H₂O + CO₂

Number of moles of CaCO₃:

Number of moles of CaCO₃ = Mass /molar mass

Number of moles of CaCO₃= 25.0 g / 100.1 g/mol

Number of moles of CaCO₃ = 0.25 mol

Number of moles of HCl:

Number of moles of HCl = Mass /molar mass

Number of moles of HCl = 13.0 g / 36.5 g/mol

Number of moles of HCl = 0.36 mol

Now we will compare the moles of CaCl₂ with HCl and CaCO₃ .

CaCO₃ : CaCl₂

1 : 1

0.25 : 0.25

HCl : CaCl₂

2 : 1

0.36 : 1/2 × 0.36 = 0.18 mol

The number of moles of CaCl₂ produced by HCl are less it will be limiting reactant.

Mass of calcium chloride:

Mass of CaCl₂ = moles × molar mass

Mass of CaCl₂ =0.18 mol × 110.98 g/mol

Mass of CaCl₂ = 20 g

5 0

3 years ago

One cup of kidney beans contains 15 g of protein, 1 g of fat, and 42 g of carbohydrate. how many kilocalories, to two significan

ollegr [7]

we need to get the total calories, we can get it by getting the average of calories of the protein, fat, and carbohydrates:
calories of protein = 15g x 4 KCal/g
= 60 KCal
calories of fat = 1 g x 9 KCal/g
= 9 kCal
calories of carbohydrates = 42 g x 4 KCal/g
= 168 Kcal
∴ the total calories = 60 + 9 + 168 = 237Kcal = 0.237 Cal
to get the resualt to two significant figures
∴ the resault is = 0.24 Cal = 240 KCal

4 0

3 years ago