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3 years ago

10:38 Fri 9 Jul

Chemistry

1 answer:

VMariaS [17]3 years ago

6 0

Answer.

Universal indicator

Explanation.

Universal indicator has many different colour changes, from red for strongly acidic solutions to dark purple for strongly alkaline solutions. In the middle, neutral pH 7 is indicated by green.

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Ice floats on water. For most other substances, however, the solid sinks in the liquid. Classify each of these statements based

sattari [20]

Answer:

1.High pressure will cause the liquid to become solid :

Describe both water and other substances

2.High pressure will cause the solid to become liquid :

It describe none : neither water nor other substances 

This statement is :False for both water and other substances

3.The solid is more dense than the liquid :

It describe other substance

This statement is :False for water but true for other substances.

4. In a phase diagram, the solid-liquid coexistence line has a negative slope.

It describes water:

This statement is :True for water because solid ice is less dense than liquid water.

False for other substance, they have positive slope

5.The molecules are closest in the liquid phase.

This statement is :False for water and other substances

6.The solid is less dense than the liquid:

It Describes water because ice is less dense than liquid water

7. In a phase diagram, the solid-liquid coexistence line has a positive slope.

It describe other substances

This statement is :True for other substances but false for water

8. The molecules are closest in the solid phase :

Describes both water and other substances

Explanation:

Answers to statement 1 , 2,5 and 8

Answers to statement 1 , 2

On increasing pressure and decreasing temperature , There occur Phase transition always for every substance :

From liquid to solid and gas to liquid

Hence,

In Both for water and other substance

High pressure will cause the liquid to become solid.

Answers to statement 5,8 :

2.The Particles of solid are closely packed hence there is maximum force of attraction between the particle of solid as compared to liquid and gases .

Hence , The molecules of both water and other substances are closest in the solid phase

This also means that in liquid molecules are far apart .

Rest statement : 3, 4 ,6 ,7 are explained below(see attached image)

The molecules are closest in the liquid phase is false statement and does not describe both water and other substance

Ice floats on water. For most other substances, however, the solid sinks in the liquid.

This can be explained using the phase diagram of water :

The line DB is = the solid-liquid coexistence line

It has negative slope because , solid ice is less dense than liquid water . That is why ice floats on water because its density is less than water

Hence Water is described truly by statement 4,6, which are :

4. the solid-liquid coexistence line has a negative slope.

6.The solid is less dense than the liquid.

Rest 3,7 = describe by other substance

other substance : Solid is more dense than the liquid ,the solid-liquid coexistence line has a positive slope

7 0

4 years ago

A baby weighs 7 pounds, 4 ounces at birth and 7 pounds, I ounce at discharge. What percent of weight did the baby lose

Aloiza [94]

Answer:

2.6%

Explanation:

As, 1 ounce (oz) = 0.0625 pounds (lb)

Therefore, weight of baby at discharge = 7 lb,1 oz = 7+0.0625 lb = 7.0625 lb

Since, 1 oz = 0.0625 lb

⇒ 4 oz = 4×0.0625 = 0.25 lb

Therefore, weight of baby at birth = 7 lb,4 oz = 7+0.25 lb = 7.25 lb

The amount of weight lost is equal to the difference of weight of the baby at birth and discharge.

Therefore, weight lost = 7.25 lb - 7.0625 lb = 0.1875 lb

Now, the percentage of weight lost by the baby is given by the amount of weight lost divided by the weight of the baby at birth.

Therefore, the percentage of weight lost = weight lost ÷ weight at birth = 0.1875 lb ÷ 7.25 lb × 100 = 2.6%

6 0

4 years ago

Calculate the mass of h2o and c6 h12 o6 required to make 250 gram of 40% solution of glucose

Sedaia [141]

40% solution of glucose is where the solution contains, by weight, 40% glucose and 60% water.

Therefore, if the total weight of the solution is 250 g,
mass of the glucose (C6H12O6) = 250 g * 40% = 100 g
mass of water (H2O) = 250 g * 60% = 150 g

Mass of water can also be calculated by subtracting the weight of glucose from the total weight of the solution:
mass of water = 250g-100g = 150g.

5 0

4 years ago

Why is tape attracted to my skin? Give explanation

shutvik [7]

Answer:

Since the tape has extra electrons, it has a negative charge. When you move your finger close to the tape, electrons in your skin are repelled and move away. This makes the skin on your finger tip have a slight positive charge. Since positive and negative attract, the tape moves toward your finger.

5 0

4 years ago

A 7.83 g sample of hcn contains 0.290 g of h and 4.06 g of n. find the mass of carbon in a sample of hcn with a mass of 3.37 g.

xeze [42]

To obey the Law of Conservation of Mass, the sum of all individual elements of a compound is equal to the mass of the compound. So, if HCN has a mass of 7.83 grams, then

7.83 g = mass of H + mass of C + mass of N

We know the masses of H and N to be 0.290 g and 4.06 g, respectively. Hence, we can find for the mass of C:

7.83 = 0.29 + mass of C + 4.06
mass of C = 3.48 g

As an extension to the Law of Conservation of Mass, there is also a Law of Definite Proportions. According to Dalton's atomic theory, a compound is formed from a fixed ratio of its individual elements. From our previous calculations, we know that the mass ratio of H to C to N is 0.29 g: 3.48 g:4.06 grams. The ratio could also be expressed in percentages. Let's find the mass percentage of Carbon in HCN to be used later:

mass % of Carbon = (3.48 g/7.83 g)*100
mass % of Carbon = 44.44%

So, if you collect a different mass of HCN, say 3.37 g, the corresponding mass of Carbon is equal to:

Mass of Carbon = (3.37)(44.44%)
Mass of Carbon = 1.498 g

3 0

4 years ago