All categories

3 years ago

4. What is the role of the benedict solution in testing for presence of carbohydrates

Chemistry

1 answer:

Vanyuwa [196]3 years ago

3 0

Answer:

it identifies reducing sugars (monosaccharide's and some disaccharides), which have free ketone or aldehyde functional group

Explanation:

It turns from turquoise to yellow or orange when it reacts with reducing sugars.

You might be interested in

1.10 The table gives the pH values of a few substances.

Phoenix [80]

Answer:

Explanation:

Acidity is from 1-6

Neutral 7

Base 8-14

4 0

3 years ago

Read 2 more answers

Carbon tetrachloride can be produced by the following reaction: Suppose 1.20 mol of and 3.60 mol of were placed in a 1.00-L flas

hjlf

The given question is incomplete. The complete question is :

Carbon tetrachloride can be produced by the following reaction:

$CS_2(g)+3Cl_2(g)\rightleftharpoons S_2Cl_2(g)+CCl_4(g)$

Suppose 1.20 mol $CS_2(g)$ of and 3.60 mol of $Cl_2(g)$ were placed in a 1.00-L flask at an unknown temperature. After equilibrium has been achieved, the mixture contains 0.72 mol of $CCl_4$ . Calculate equilibrium constant at the unknown temperature.

Answer: The equilibrium constant at unknown temperature is 0.36

Explanation:

Moles of $CS_2$ = 1.20 mole

Moles of $Cl_2$ = 3.60 mole

Volume of solution = 1.00 L

Initial concentration of $CS_2$ = $\frac{moles}{volume}=\frac{1.20mol}{1L}=1.20M$

Initial concentration of $Cl_2$ = $\frac{moles}{volume}=\frac{3.60mol}{1L}=3.60M$

The given balanced equilibrium reaction is,

$CS_2(g)+3Cl_2(g)\rightleftharpoons S_2Cl_2(g)+CCl_4(g)$

Initial conc. 1.20 M 3.60 M 0 0

At eqm. conc. (1.20-x) M (3.60-3x) M (x) M (x) M

The expression for equilibrium constant for this reaction will be,

$K_c=\frac{[S_2Cl_2]\times [CCl_4]}{[Cl_2]^3[CS_2]}$

Now put all the given values in this expression, we get :

$K_c=\frac{(x)\times (x)}{(3.60-3x)^3\times (1.20-x)}$

Given :Equilibrium concentration of $CCl_4$ , x = $\frac{moles}{volume}=\frac{0.72mol}{1L}=0.72M$

$K_c=\frac{(0.72)\times (0.72)}{(3.60-3\times 0.72)^3\times (1.20-0.72)}$

$K_c=0.36$

Thus equilibrium constant at unknown temperature is 0.36

4 0

3 years ago

The density of ice is _____ that of liquid water. a. greater than b. equal to c. less than

Talja [164]

The correct option is C.

The density of an object refers to its mass per volume. Water and ice have different densities. The differences in their densities is due to the empty spaces which exist in the structure of ice. Because of the empty spaces, the structure of ice occupy more volume than that of water, hence it is less dense than water.

4 0

3 years ago

Read 2 more answers

Which of the following is least likely to dissolve in the polar solvent water?

s2008m [1.1K]

<span>Like dissolves like and unlike repels like. This applies to the polarity of the solutions. Polar dissolves polar and non-polar does not mix with polar solutions. In this case, the polar substance that can mix with water. Sugar and salt can be dissolved through agitation. Oil which is nonpolar is immiscible in water. Hence answer is D. </span>

6 0

3 years ago

In a titration, 45.0 mL of KOH is neutralized by 75.0 mL of 0.30M HBr. How much KOH is in 1.0 liter of the KOH solution ?

photoshop1234 [79]

KOH + HBr ---> KBr + H2O

0,3 moles of HBr ---in-------1000ml
x moles of HBr-------in------75ml
x = 0,0225 moles of HBr

according to the reaction: 1 mole of KOH = 1 mole of HBr
so
0,0225 moles of HBr = 0,0225 moles of KOH

0,0225 mole of KOH------in-----45ml
x moles of KOH -----------in------1000ml
x = 0,5 moles of KOH

answer: 0,5 mol/dm³ KOH (molarity)

8 0

3 years ago