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3 years ago

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Chemistry

1 answer:

balu736 [363]3 years ago

5 0

Answer:

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Explanation:

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When ammonium nitrate is dissolved in water in a glass container, the glass container becomes cold. Is this an endothermic or ex

Trava [24]

Answer:

Explanation:

Figure 6. An instant cold pack consists of a bag containing solid ammonium nitrate and a second bag of water. When the bag of water is broken, the pack becomes cold because the dissolution of ammonium nitrate is an endothermic process that removes thermal energy from the water.

8 0

2 years ago

Match the following descriptions with the correct polysaccharide, note if you answer any part of this question incorrectly a sig

Ad libitum [116K]

Answer:

Glycogen. Cellulose. Amylose. Cellulose. Amylopetin and Glycogen. Amylopetin and Cellulose.

Explanation:

Glycogen is the form that glucose is stored in human body.

Cellulose is the structural part of plant cell walls and human cannot digest it.

Amylose is the polysaccharide linked mainly by the the bonds of $\alpha$ 1,4 glycosidic.

Cellulose is an unbranched polysaccharide linked mainly by the bonds of $\beta$ 1,4 glycosidic.

Amylopetin and Glycogen are branched polysaccharides linked by the bonds of $\alpha$ 1,4 glycosidic and $\alpha$ 1,6 glycosidic.

Amylopetin and Cellulose are mainly stored in plants.

4 0

3 years ago

Aspirin (acetylsalicylic acid, C9H8O4) is a weak monoprotic acid. To determine its acid-dissociation constant, a student dissolv

Triss [41]

Answer:

1. $3.57\times 10^{-4}$ was the $K_a$ value calculated by the student.

2. $5.93\times 10^{-4}$ was the $K_b$ of ethylamine value calculated by the student.

Explanation:

The $pH$ value of Aspirin solution = 2.62

$pH=-\log[H^+]$

$[H^+]=10^{-2.62}=0.00240 M$

Moles of s asprin = $\frac{2.00 g}{180 g/mol}=0.01111 mol$

Volume of the solution = 0.600 L

The initial concentration of Aspirin = c = $\frac{0.01111 mol}{0.600 L}=0.0185 M$

$HAs\rightleftharpoons As^-+H^+$

initially

c 0 0

At equilibrium

(c-x) x x

The expression of dissociation constant :

$K_a=\frac{[As^-][H^+]}{[HAs]}$ :

$K_a=\frac{x\times x }{(c-x)}$

$=\frac{0.00240 M\times 0.00240 M}{(0.0185-0.00240 )}$

$K_a=3.57\times 10^{-4}$

$3.57\times 10^{-4}$ was the $K_a$ value calculated by the student.

The $pH$ value of ethylamine = 11.87

$pH+pOH=14$

$pOH=14-11.87=2.13$

$pOH=-\log[OH^-]$

$[OH^-]=10^{-2.13}=0.00741 M$

The initial concentration of ethylamine = c = 0.100 M

$C_2H_5NH_2+H_2O\rightleftharpoons C_2H_5NH_3^{+}+OH^-$

initially

c 0 0

At equilibrium

(c-x) x x

The expression of dissociation constant :

$K_b=\frac{[C_2H_5NH_3^{+}][OH^-]}{[C_2H_5NH_2]}$ :

$K_b=\frac{x\times x}{(c-x)}$

$=\frac{0.00741\times 0.00741}{(0.100-0.00741)}$

$K_b=5.93\times 10^{-4}$

$5.93\times 10^{-4}$ was the $K_b$ of ethylamine value calculated by the student.

3 0

3 years ago

Which factor can increase the potential energy of an object?

OLEGan [10]

Answer:

Increase in height from the ground.

Explanation:

Potential energy =mass×acceleration due to gravity×height.

P.E= mgh

4 0

3 years ago

HELP

tatiyna

Answer:

Bi (Bismuth)

Ag (Silver)

Li (Lithium)

Explanation:

Xe (Xenon) and I (Iodine) are non-metals. They cannot from a metallic bond because metallic bonds are bonds between metals only.

7 0

3 years ago