Answer:
bdbdndnfnfnfnfnfnfnfnffnf
Answer:
n = 0.207 mole
Explanation:
We have,
P = 1 atm
V = 5 liter
R = 0.0821 L.atm/mol.K
T = 293 K
We need to find the value of n. The relation is as follows :
PV = nRT
Solving for n,
So, the value of n is 0.207 mol.
1) Answer: A hot pack feels warm when chemicals in it combine.
Explanation: Reactions or process in which heat is released(produced) are known as exothermic reactions or process and those in which the heat is absorbed are known as endothermic reactions or process.
If a beaker feels cools when chemical in it react then it means the chemicals have absorbed the heat energy from its surroundings and so it is an example of an endothermic process.
A hot pack feels warm when chemicals in it combine means the energy is released in the chemical reaction and so it is an example of an exothermic process.
Plants use the sun's energy for photosynthesis which is a process of forming food for the plants. Energy acts as a reactant in this process and so it is an example of endothermic process.
Frying an egg by heating it on a stove is an example of an endothermic process as the heat is required to fry the egg.
So, the only exothermic process is the second one, "A hot pack feels warm when chemicals in it combine."
2) In the given equation, heat is written as a product means the heat is released in the equation and so it is an example of an exothermic reaction.
So, the correct choice is the last one " It is exothermic because energy is released."
The molecular formula is calculated as follows
that is for carbon = 26.7/12= 2.23 moles
hydrogen= 2.24/1=2.24 moles
oxygen= 71.1/16=4.44 moles
<h3> What is molecular formula?</h3>
A chemical formula is a way to describe the chemical ratios of the atoms that make up a specific chemical compound or molecule in chemistry. Chemical element symbols, numbers, and occasionally other symbols, such as parentheses, dashes, brackets, commas, and plus (+) and minus () signs, are used to represent the chemical elements. These can only include one typographic line of symbols, which may also include subscripts and superscripts. A chemical formula has no words and is not the same as the chemical name. A chemical formula does not equal a complete chemical structural formula, despite the fact that it may suggest some basic chemical structures. Chemical formulae are often less powerful than chemical names and structural formulae, and they can only fully describe the structure of the simplest molecules and chemical compounds.
To learn more about molecular formula from the given link:
brainly.com/question/14425592
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NaHCO3 is the right answer
