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3 years ago

Identify the following statements as either True or False.

Chemistry

1 answer:

pantera1 [17]3 years ago

7 0

Answer:

Carbohydrates are polyhydroxy aldehydes, ketones, or compounds that yield polyhydroxy aldehydes or ketones upon hydrolysis. FALSE

Monosaccharides exist as cyclic structures containing functional groups such as hydroxyl groups, acetal (ketal), and hemiacetal (hemiketal). TRUE

A carbohydrate can be classified as a monosaccharide, disaccharide, or polysaccharide TRUE

Disaccharides exist as cyclic structures that only contain hemiacetal (or hemiketal) groups. FALSE

Explanation:

carbohydrates consists of a long cyclic chain of monosaccharides. They are polysaccharides and exist in the cyclic structure. It is only the individual monosaccharides that contain the aldehyde or ketone group as the case may be.

When completely hydrolysed monosaccharides are formed from polysaccharides which are cyclic hemiacetals and acetals containing the hydroxyl functional group.

Carbohydrates containing only one sugar unit is a monosaccharide, if it contains two sugar units it is a diasaccharide, it contains more than two sugar units it is a polysaccharide.

Diasaccharides such as fructose also contain hemiacetal or hemiketal groups and -OH groups also.

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A steel container filled with H₂ gas is at a pressure of 6.5 atm and a temperature of 22°C. If the container is placed near a fu

Yuki888 [10]

Answer: The new pressure is 7.1 atm

Explanation:

To calculate the final pressure of the system, we use the equation given by Gay-Lussac Law. This law states that pressure of the gas is directly proportional to the temperature of the gas at constant pressure.

Mathematically,

$\frac{P_1}{T_1}=\frac{P_2}{T_2}$

where,

$P_1\text{ and }T_1$ are the initial pressure and temperature of the gas.

$P_2\text{ and }T_2$ are the final pressure and temperature of the gas.

We are given:

$P_1=6.5atm\\T_1=22^0C=(22+273)K=295K\\P_2=?\\T_2=50^0C=(50+273)K=323K$

Putting values in above equation, we get:

$\frac{6.5}{295}=\frac{P_2}{323}\\\\P_2=7.1$

Hence, the new pressure is 7.1 atm

8 0

3 years ago

Which of the following would cause a decrease in the volume of a sealed balloon filled with air? (2 points) addition of another

monitta

A decrease in temperature will cause a decrease in the volume of a sealed balloon filled with air. Temperature and pressure usually act together.This is because, reducing the temperature of a volume of gas will reduce the kinetic energy of the atoms of the gas, leading to a slower movement of the atoms and thus reducing the number of time the particles of the gas collide will the wall of the container; this means that the pressure has been reduced. This will reduce the volume of the gas. The reverse is also true.

7 0

4 years ago

What are the two major types of<br> compounds? How do the bonds differ in<br> each type?

Kaylis [27]

Answer:

1= Ionic compounds

2= Covalent compounds

Explanation:

Ionic bond:

It is the bond which is formed by the transfer of electron from one atom to the atom of another element.

Both bonded atoms have very large electronegativity difference. The atom with large electronegativity value accept the electron from other with smaller value of electronegativity.

For example:

Sodium chloride is ionic compound. The electronegativity of chlorine is 3.16 and for sodium is 0.93. There is large difference is present. That's why electron from sodium is transfer to the chlorine. Sodium becomes positive and chlorine becomes negative ion.

Covalent bond:

It is formed by the sharing of electron pair between bonded atoms.

The atom with larger electronegativity attract the electron pair more towards it self and becomes partial negative while the other atom becomes partial positive.

For example:

In water the electronegativity of oxygen is 3.44 and hydrogen is 2.2. That's why electron pair attracted more towards oxygen, thus oxygen becomes partial negative and hydrogen becomes partial negative.

6 0

4 years ago

Liquid octane will react with gaseous oxygen to produce gaseous carbon dioxide and gaseous water . Suppose 97. g of octane is mi

zhannawk [14.2K]

Answer: 61 grams

Explanation:

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

$\text{Number of moles of octane}=\frac{\text{Given mass}}{\text{Molar mass}}=\frac{97g}{114g/mol}=0.85moles$

$\text{Number of moles of oxygen}=\frac{\text{Given mass}}{\text{Molar mass}}=\frac{150g}{32g/mol}=4.69moles$

The chemical equation for the combustion of octane in oxygen follows the equation:

$2C_8H_{18}+25O_2\rightarrow 16CO_2+18H_2O$

By stoichiometry of the reaction;

25 moles of oxygen react with 2 moles of octane

4.69 moles of oxygen react with= $\frac{2}{25}\times 4.69=0.37$ moles of octane

Thus, oxygen is the limiting reagent as it limits the formation of product and octane is the excess reagent.

25 moles of oxygen produce 18 moles of water

4.69 moles of oxygen produce= $\frac{18}{25}\times 4.69=3.38$ moles of water.

Mass of water produced= $moles\times {\text{Molar mass}}=3.38\times 18g/mol=61g$

The maximum mass of water that could be produced by the chemical reaction is 61 grams.

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3 years ago

Which of the following describes an element? Choose all that apply.

Svetradugi [14.3K]

Answer: Element is a substance that is made entirely from one type of atom. For example, the element hydrogen is made from atoms containing a single proton and a single electron

Explanation:a b d

8 0

3 years ago