All categories

2 years ago

PLEASE HELP!

Chemistry

2 answers:

fgiga [73]2 years ago

5 0

150/30 = 5
HF1 20/2 = 10
HF2 10/2 = 5
HF3 5/2 = 2.5
HF4 2.5/2 = 1.25
HF5 1.25/2 = 0.625
Answer: 0.63g

NikAS [45]2 years ago

4 0

Answer: 0,63 g

Explanation: During 150 days 5 decays happen. You can write a set

of masses : 20 g ⇒ 10 g after first decay, then 5 g , 2.5 g , 1,25 g

and after fifth decay 0.63 g

You might be interested in

What is the name of this alkane? two central carbons are bonded to c h 3 at each end, h below, and c h3 above the left carbon an

Kazeer [188]

The name of this alkane is with central carbons are bonded to c h 3 is 2-methylbutane.

<h3>What is alkane?</h3>

Alkanes belong to the family of saturated hydrocarbons with carbon carbon single bond.

For the given alkane;

CH₃ H

CH₃ - C - C - CH₃

H H

Thus, the name of this alkane is with central carbons are bonded to c h 3 is 2-methylbutane.

Learn more about alkane here: brainly.com/question/24270289

#SPJ4

4 0

1 year ago

Which type of bonding is most important in ch3ch2ch2ch2ch2ch3?

saveliy_v [14]

The compound $CH_3CH_2CH_2CH_2CH_2CH_3$ is formed only by sharing of electrons between the atoms. The structure of the compound is shown in the image.

Each line between two atoms represents the sharing of an electron pair which results in the formation of a single bond. Since, carbon has 4 electrons in its valence shell and hydrogen has 1 electron in its valence shell so in order to complete the octet ( to have 8 electrons in their valence shell, noble gas configuration) to attain stability carbon needs 4 more electrons and hydrogen needs 1 electron. So, sharing of electron will occur as shown in the image and the formed compound is stable in nature.

Since, the bond that is formed by sharing of electrons between atoms is known as covalent bond. So, covalent bonding is most important in $CH_3CH_2CH_2CH_2CH_2CH_3$ .

7 0

3 years ago

A Calorie unit used in food is equal to the amount of energy necessary to raise the temperature of 1 kilogram of water ________

Kitty [74]

A Calorie unit used in food is equal to the amount of energy necessary to raise the temperature of 1 kilogram of water by 1 degrees Celsius.

<h3>What is One Calorie ?</h3>

The amount of heat energy required to raise the temperature by 1 gram of water through 1°C is known as One Calorie.

1 Calorie = 4.18 J

Thus from the above conclusion we can say that A Calorie unit used in food is equal to the amount of energy necessary to raise the temperature of 1 kilogram of water by 1 degrees Celsius.

Learn more about the One calorie here: brainly.com/question/1061571

#SPJ4

7 0

2 years ago

Classify each of the following as a homogeneous or heterogeneous substance.

Mnenie [13.5K]

Answer:

a). iron ore - is a heterogeneous substance.

b). quartz - is a homogeneous substance.

c). granite - is a heterogeneous substance.

d). energy drink - is a heterogeneous substance.

e). oil-and-vinegar salad dressing - is a heterogeneous substance.

f). salt - is a homogeneous substance.

g). rainwater - is a heterogeneous substance.

h). nitrogen - is a homogeneous substance.

Explanation:

a). iron ore - is a heterogeneous substance as iron core contains iron and other impurities

b). quartz - is a homogeneous substance as it is only made up of carbon

c). granite - is a heterogeneous substance as it is made up of multiple minerals.

d). energy drink - is a heterogeneous substance as it contains various substances mixed in it

e). oil-and-vinegar salad dressing - is a heterogeneous substance as oil and vinegar itself are different compounds

f). salt - is a homogeneous substance as it only contains one type of molecule

g). rainwater - is a heterogeneous substance as it contains water and other minerals

h). nitrogen - is a homogeneous substance as it is only made of one type of molecule.

5 0

10 months ago

The vapor pressure of pure water at 25 °c is 23.8 torr. What is the vapor pressure (torr) of water above a solution prepared by

maxonik [38]

The vapour pressure of the solution is 23.4 torr.

Use Raoult’s Law to calculate the vapour pressure:

p₁ = χ₁p₁°

where

χ₁ = the mole fraction of the solvent

p₁ and p₁° are the vapour pressures of the solution and of the pure solvent

The formula for vapour pressure lowering Δp is

Δp = p₁° - p₁

Δp = p₁° - χ₁p₁° = p₁°(1 – χ₁) = χ₂p₁°

where χ₂ is the mole fraction of the solute.

Step 1. Calculate the mole fraction of glucose

n₂ = 18.0 g glu × (1 moL glu/180.0 g glu) = 0.1000 mol glu

n₁ = 95.0 g H_2O × (1 mol H_2O/18.02 g H_2O) = 5.272 mol H_2O

χ₂ = n₂/(n₁ + n₂) = 0.1000/(0.1000 + 5.272) = 0.1000/5.372 = 0.018 62

Step 2. Calculate the vapour pressure lowering

Δp = χ₂p₁° = 0.018 62 × 23.8 torr = 0.4430 torr

Step 3. Calculate the vapour pressure

p₁ = p₁° - Δp = 23.8 torr – 0.4430 torr = 23.4 torr

3 0

3 years ago