A 23.0% by mass LiCl solution is prepared in water. What is the mole fraction of the water? 0.113 0.887 0.873 0.127 0.911

Hafnium has six naturally occurring isotopes: 0.16% of 174Hf, with an atomic weight of 173.940 amu; 5.26% of 176Hf, with an atom

ser-zykov [4K]

Answer:

177.277amu

Explanation:

the total occuring isotopes for Hafnium is =6.

First isotope had an atomic weight of 173.940amu

Second isotope =175.941amu

Third isotope =176.943amu

Fourth isotope=177.944amu

Fifth isotope. =178.946amu

sixth isotope .179.947amu

Average atomic weight of Hafnium= sum of all the atomic weights of the isotopes/ Total occuring isotopes

Thus, 173.940amu+175.941amu+176.943amu+177.944amu+178.946amu+179.947amu.= 1063.661amu

Average atomic weight= 1063.661amu /6 = 177.2768333amu

= 177.277amu to 3 decimal places.

6 0

2 years ago

A student heats a sample of Copper (II) sulfate in a crucible and records the data shown in the table. What is the complete form

liberstina [14]

Explanation:

Copper (II) sulfate is usually present as a hydrous state, which is of the form CuSO4 * nH2O, where n is a whole number.

Mass of sample (CuSO4 * nH2O)

= 152.00g - 128.10g = 23.90g.

Mass of water loss during heating

= 152.00g - 147.60g = 4.40g.

Molar mass of H2O = 18g/mol

Moles of H2O in sample

= 4.40g / (18g/mol) = 0.244mol.

Mass of anhydrous sample (CuSO4)

= 23.90g - 4.40g = 19.50g

Molar mass of CuSO4 = 159.61g/mol

Moles of CuSO4 in sample

= 19.50g / (159.61g/mol) = 0.122mol.

Since mole ratio of CuSO4 to H2O

= 0.122mol : 0.244mol = 1:2, n = 2.

Hence we have CuSO4 * 2H2O.

6 0

2 years ago

Read 2 more answers

The first eighteen chemical elements on the periodic table are described below in a series of statements. The first 1S letters o

Aleonysh [2.5K]

Answer: The questions looks unclear

Explanation: Periodic table is a table that contains elements arranged according to their increasing atomic number.

1. D belongs to group 4

E. Belongs to group 7

B belongs to group 1

A belongs to group 8. A noble gas.

R belongs to group 3. K belongs to group 6 C belongs to group 1. H belongs to group 8

3 0

2 years ago

A turtle moves at a speed of 1.0km/h. How fast is the turtle moving in meter per second (m/s)?

ahrayia [7]

Answer:

0.28m/s

Explanation:

Speed is defined as the distance travelled per unit of time. The speed of the turtle is 1.0km/h. Thus, to find the speed in m/s, we need to convert km to m (1km is 1000m), and h to s (1h = 3600s).

Converting units:

1.0km/h * (1000m / 1km) * (1h / 3600s) = 0.28m/s.

The speed of the turtle in meter per second is 0.28m/s

7 0

2 years ago

Consider a culture medium on which only gram-positive organisms such as Staphylococcus aureus colonies can grow due to an elevat

Olin [163]

<h2>Selective & Differential Medium</h2>

Explanation:

Selective media allow specific types of organisms to develop, and inhibit the development of different living beings. The selectivity is cultivated in a few ways.For model, living beings that can use a given sugar are handily screened by making that sugar the main carbon source in the medium. On the other hand,selective hindrance of certain sorts of microorganisms can be accomplished by adding dyes, anti-infection agents, salts or explicit inhibitors which influence the digestion or enzyme systems of the living beings
Differential media are utilized to separate firmly related life forms or groups of living beings. owing to the pre of specific colors or synthetic compounds in the media, the creatures will deliver trademark changes or development designs that are utilized for ID or separation. An assortment of particular and differential media are utilized in clinical, demonstrative and water contamination research facilities, and in food and dairy laboratories
Selective media because elevated NaCI level is designed to help grow selective bacteria.differential media because the fermented sugar gives off a yellow halo which allows for differentiate between bacteria

4 0

2 years ago