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.
Answer:
9 (1-2x²)
Explanation:
The given expression is:
30 - 9x²*2 - 21 - 4 + 4
The first step is to compute the multiplication. This will give:
30 - 18x² - 21 - 4 + 4
Then, we will add like terms as follows:
(30-21-4+4) - 18x²
= 9 - 18x²
Finally, we can take the 9 as a common factor from both terms, this will give:
9 (1-2x²)
Hope this helps :)
Answer:
Charged objects have an imbalance of charge - either more negative electrons than positive protons or vice versa. And neutral objects have a balance of charge - equal numbers of protons and electrons. ... Their presence (or absence) will have no direct bearing upon whether an object is charged or uncharged.
Answer:
2.05*10⁻⁵ moles of CF₂ can dissolve in 100 g of water.
12.82 moles of CaF₂ will dissolve in exactly 1.00 L of solution
Explanation:
First, by definition of solubility, in 100 g of water there are 0.0016 g of CaF₂. So, to know how many moles are 0.0016 g, you must know the molar mass of the compound. For that you know:
- Ca: 40 g/mole
- F: 19 g/mole
So the molar mass of CaF₂ is:
CaF₂= 40 g/mole + 2*19 g/mole= 78 g/mole
Now you can apply the following rule of three: if there are 78 grams of CaF₂ in 1 mole, in 0.0016 grams of the compound how many moles are there?
moles=2.05*10⁻⁵
<u><em>2.05*10⁻⁵ moles of CF₂ can dissolve in 100 g of water.</em></u>
Now, to answer the following question, you can apply the following rule of three: if by definition of density in 1 mL there is 1 g of CaF₂, in 1000 mL (where 1L = 1000mL) how much mass of the compound is there?
mass of CaF₂= 1000 g
Now you can apply the following rule of three: if there are 78 grams of CaF₂ in 1 mole, in 1000 grams of the compound how many moles are there?
moles=12.82
<u><em>12.82 moles of CaF₂ will dissolve in exactly 1.00 L of solution</em></u>
