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sergij07 [2.7K]
3 years ago
13

What is not true about most combustion reactions?

Chemistry
1 answer:
vazorg [7]3 years ago
6 0
Combustion, or burning,[1] is a high-temperature exothermic redox chemical reaction between a fuel (the reductant) and an oxidant, usually atmospheric oxygen, that produces oxidized, often gaseous products, in a mixture termed as smoke. Combustion in a fire produces a flame, and the heat produced can make combustion self-sustaining. Combustion is often a complicated sequence of elementary radical reactions. Solid fuels, such as wood and coal, first undergo endothermic pyrolysis to produce gaseous fuels whose combustion then supplies the heat required to produce more of them. Combustion is often hot enough that incandescent light in the form of either glowing or a flame is produced. A simple example can be seen in the combustion of hydrogen and oxygen into water vapor, a reaction commonly used to fuel rocket engines. This reaction releases 242 kJ/mol of heat and reduces the enthalpy accordingly (at constant temperature and pressure):

2H
2(g) + O
2(g) → 2 H2O(g)

Combustion of an organic fuel in air is always exothermic because the double bond in O2 is much weaker than other double bonds or pairs of single bonds, and therefore the formation of the stronger bonds in the combustion products CO2 and  H2O results in the release of energy.[2] The bond energies in the fuel play only a minor role, since they are similar to those in the combustion products; e.g., the sum of the bond energies of CH4 is nearly the same as that of CO2. The heat of combustion is approximately -418 kJ per mole of O2 used up in the combustion reaction, and can be estimated from the elemental composition of the fuel.[2]

Uncatalyzed combustion in air requires fairly high temperatures. Complete combustion is stoichiometric with respect to the fuel, where there is no remaining fuel, and ideally, no remaining oxidant. Thermodynamically, the chemical equilibrium of combustion in air is overwhelmingly on the side of the products. However, complete combustion is almost impossible to achieve, since the chemical equilibrium is not necessarily reached, or may contain unburnt products such as carbon monoxide, hydrogen and even carbon (sootor ash). Thus, the produced smoke is usually toxic and contains unburned or partially oxidized products. Any combustion at high temperatures in atmospheric air, which is 78 percent nitrogen, will also create small amounts of several nitrogen oxides, commonly referred to as NOx, since the combustion of nitrogen is thermodynamically favored at high, but not low temperatures. Since combustion is rarely clean, flue gas cleaning or catalytic converters may be required by law.

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Suppose that you put a mass of 10 g of hydrochloric acid and 20 g of magnesium bicarbonate into the reaction; however, you only
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It would be around 10 grams

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6+4

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How many mol of C7H16 would you have if you have 76.36 grams? Give your answer to 2 decimal spaces.
tensa zangetsu [6.8K]

0.761 mol of C_7H_{16}  would you have if you have 76.36 grams.

<h3>What is a mole?</h3>

A mole is defined as 6.02214076 × 10^{23}of some chemical unit, be it atoms, molecules, ions, or others. The mole is a convenient unit to use because of the great number of atoms, molecules, or others in any substance.

Given data:

Mass=76.36 grams

Moles = \frac{mass}{molar \;mass}

Moles = \frac{76.36 grams}{100.21 g/mol}

Moles = 0.761

Hence,  0.761 mol of  C_7H_{16} would you have if you have 76.36 grams.

Learn more about moles here:

brainly.com/question/8455949

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The diagram shows a plant cell.
Serga [27]

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B. structure 2

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A 0.8115 g sample of HCl was placed into a 50 mL volumetric flask and the sample was thoroughly dissolved in water to make 50 mL
inysia [295]

Answer:

Molarity of NaOH solution is 1.009 M

Explanation:

Molar mass of HCl is 36.46 g/mol

Number moles = (mass)/(molar mass)

So, 0.8115 g of HCl = \frac{0.8115}{36.46}moles HCl = 0.02226 moles HCl

1 mol of NaOH neutralizes 1 mol of HCl.

So, if molarity of NaOH solution is S(M) then moles of NaOH required to reach endpoint is \frac{S\times 22.07}{1000}moles

So, \frac{S\times 22.07}{1000}=0.02226

or, S = 1.009

So, molarity of NaOH solution is 1.009 M

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What equation in the blast furnace extraction of iron is not a redox reaction?
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The decomposition of limestone CaCO3 > CaO + CO2

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