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3 years ago

Which of the following is NOT an exothermic reaction?

Chemistry

1 answer:

nignag [31]3 years ago

7 0

Answer:

a) dissolving sugar in water to form a mixture of sugar and water

Explanation:

exothermic reaction is reaction in which is heat is released during the reaction and endothermic reaction is a reaction in which heat is needed or required for the reaction to take place

all the options excluding option A) is exothermic as during the process of formation of bonds in oxidation, heat is released. rusting too is a slow form of oxidation and thus an exothermic reaction.

dissolving sugar in water is not exothermic reaction because their is no heat released. the sugar molecules simply disperses in the water molecules and form a solution.

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If 57.3 l of 0.497 m koh is required to completely neutralize 39.5 l of a CH3COOH solution. What is the molarity of the acetic a

bearhunter [10]

The molarity of the solution will be 0.72 m.

The majority of reactions take place in solutions, making it crucial to comprehend how the substance's concentration is expressed in a solution when it is present. The number of chemicals in a solution can be stated in a variety of ways, including.

The symbol for it is M, and it serves as one of the most often used concentration units. Its definition states how many moles of solute there are in a liter of solution.

Given data:

$V_{1} =57.3 L\\V_{2} = 39.5 L\\M_{1} = 0.497 m\\\\M_{2} = ?$

Molarity can be determined by the formula:

$M_{1} V_{1} = M_{2} V_{2}$

where, M is molarity and V is volume.

Put the value of given data in above equation.

57.3 × 0.497 m = M × 39.5 L

M = 0.72 m

Therefore, the molarity of the solution will be 0.72 m

To know more about molarity

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6 0

2 years ago

Assuming all volume measurements are made at the same temperature and pressure, how many liters of oxygen gas would it take to r

EleoNora [17]

2H2 (g) + O2 (g) -->2H2 O(g)
mole ratio of H2:O2=2:1
7.25/2=3.625

3 0

3 years ago

If 20.0 grams of Al is placed into a solution containg

meriva

Answer:

m H2(g) = 2.241 g H2(g)

Explanation:

2Al(s) + 3H2SO4(aq) → Al2(SO4)3(aq) + 3 H2(g)

limit reagent:

∴ Mw Al = 26.982 g/mol

∴ Mw H2SO4 = 98.0785 g/mol

⇒ n Al = (20 g Al)×(mol/26.982 g) = 0.7412 mol Al

⇒ n H2SO4 = ( 115 g H2SO4 )×(mol/98.0785 g) = 1.173 mol H2SO4

⇒ n H2 = (0.7412 mol Al)×(3 mol H2/ 2 mol Al) = 1.112 mol H2

∴ Mw H2 = 2.016 g/mol

⇒ g H2 = (1.112 mol H2)×(2.016 g/mol) = 2.241 g H2

5 0

3 years ago

Consider the following balanced reaction. How many grams of water are required to form 75.9 g of HNO3? Assume that there is exce

Iteru [2.4K]

Answer:

10.85 g of water

Explanation:

First we write the balanced chemical equation

$3NO_{2} +H_{2}O -->2HNO_{3} +NO$

Then we calculate the number of moles of nitric acid produced

n(HNO3) = $\frac{mass}{molar mass} =\frac{75.9g}{63.02g/mol}=1.2044 mol$

According to the balanced equation, water needed in moles is always half the number of moles of HNO3 produced. So since we will produce 1.2044 mol of HNO3, we will need 0.6022 mol of water. Now to calculate what mass that is:

mass(water)=number of moles*molar mass=0.6022mol*18.02g/mol=10.85g

5 0

3 years ago

Sulfur has an atomic mass of 32 u and Avogadro's number is 6 × 1023 formula units/mole. The number of sulfur atoms in 1 g of sul

Vikki [24]

Answer:

The number of sulfur atoms in 1 g of sulfur is:- $1.875\times 10^{22}$ atoms

Explanation:

Avogadro’s number represent the number of the constituent particles which are present in one mole of the substance. It is named after scientist Amedeo Avogadro and is denoted by $N_0$ .

Avogadro constant:-

$N_a=6\times 10^{23}$

Given atomic mass of sulfur = 32 u

Which means that:-

32 g of sulfur contains $6\times 10^{23}$ of atoms

Also,

1 g of sulfur contains $\frac {6\times 10^{23}}{32}$ of atoms

<u>So, The number of sulfur atoms in 1 g of sulfur is:- $1.875\times 10^{22}$ atoms</u>

6 0

3 years ago