1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
topjm [15]
3 years ago
13

You find a compound composed only of element "X" and hydrogen, and know that it is 91.26% element X by mass. Each molecule has 2

.67 times as many H atoms as X atoms. What is element X?
Chemistry
2 answers:
worty [1.4K]3 years ago
4 0
Since you know the ratio of atoms, you can start to put a formula togeter. The formula might look like:<span>
X<span>H2.67 
</span></span>but since atoms can't come in fractional amounts, we have to multiply the formula by some number in order to turn 2.67 into a whole #, while still maintaining the ratio. Multiplying 2.67 by 3 yields 8, so the most likely ratio in the molecule is

X3H8<span>so the ratio of 1:2.67 is still maintained. The mass percent tells you that out of every 100g of compound, 91.26g is element X, so the other 8.74g must be H. Dividing each mass by the number of moles in the formula gets us the molar mass of each element (approximately). DIviding 8.74g by 8 gets 1.09, roughly the molar mass of hydrogen. Dividing 91.26g by 3 gets us 30.4, roughly the molar mass of phosphorus. Element X is most likely phosphorus</span>
AlekseyPX3 years ago
3 0

Answer:

The element X is silicon.

Explanation:

Percentage of element X in compound molecule = 91.26%

Number of X element atom in a molecule = n

Number of hydrogen atom in a molecule = n × 2.67

Molecular formula of compound = H_{2.67n}X_{n}=H_{267}X_{100}

Let the atomic mass of element X = m

Molar mass of compound =267 g/mol+100m

Percentage of an element in a compound:

\%=\frac{\text{Number of atoms of element}\times \text{Atomic mass of element}}{\text{molecular mass of compound}}\times 100

91.26\%=\frac{100 m}{267 g/mol+100m}\times 100

m = 27.87 g/mol ≈ 28 g/mol

The element X is silicon.

You might be interested in
What unit is not a measured volume
kodGreya [7K]
The base units of length and volume are linked in the metric system. By definition, a liter<span> is equal to the volume of a cube exactly 10 </span>cm<span> tall, 10 </span>cm<span> long, and 10 </span>cm<span> wide. Because the volume of this cube is 1000 cubic </span>centimeters<span> and a </span>liter<span> contains 1000 milliliters, 1 milliliter is equivalent to 1 cubic centimeter.</span>
4 0
3 years ago
Whic number of the periodic table is the atomic number and which number is the atomic mass?
Anettt [7]

Answer:

The mass number (represented by the letter A) is defined as the total number of protons and neutrons in an atom. Consider the element helium. Its atomic number is 2, so it has two protons in its nucleus.

The atomic mass of a single atom is simply its total mass and is typically expressed in atomic mass units or amu. By definition, an atom of carbon with six neutrons, carbon-12, has an atomic mass of 12 amu.

5 0
3 years ago
At what temperature does water become a gas?
uranmaximum [27]
The answers is d. 100o c
3 0
3 years ago
Read 2 more answers
Classify each of the following as a physical or a chemical change. Give
hjlf

Answer:

a is a physical changes

b is physical changes

c is a Chemical change

d is a physical changes

5 0
3 years ago
How many molecules of CaCl2 are equivalent to 75.9 g CaCl2
sergij07 [2.7K]
First, you need to find:
One mole of CaCl_{2} is equivalent to how many grams?

Well, for this you have to look up the periodic table. According to the periodic table:
The atomic mass of Calcium Ca = 40.078 g (See in group 2)
The atomic mass of <span>Chlorine Cl = 35.45 g (See in group 17)
</span>
As there are two atoms of Chlorine present in CaCl_{2}, therefore, the atomic mass of CaCl_{2} would be:

Atomic mass of CaCl_{2}  = Atomic mass of Ca + 2 * Atomic mass of Cl

Atomic mass of CaCl_{2} = 40.078 + 2 * 35.45 = 110.978 g

Now,

110.978 g of CaCl_{2} = 1 mole.
75.9 g of CaCl_{2} = \frac{75.9}{110.978} moles = 0.6839 moles.

Hence,
The total number of moles in 75.9g of CaCl_{2} = 0.6839 moles

According to <span>Avogadro's number,
1 mole = 1 * </span>6.022 * 10^{23} molecules
0.6839 moles = 0.6839 * 6.022 * 10^{23} molecules = 4.118*10^{23} molecules

Ans: Number of molecules in 75.9g of  CaCl_{2} =  4.118*10^{23} molecules

-i


3 0
3 years ago
Read 2 more answers
Other questions:
  • According to the website of the National Aeronautics and Space Administration (NASA), the average temperature of the universe is
    12·1 answer
  • Which of the following phrases best describes a synthesis reaction?
    10·1 answer
  • The atomic number of nitrogen is 7. The number of electrons a neutral nitrogen atom has is _______ , and its atomic mass is appr
    12·2 answers
  • What was concluded about the structure of the atom as the result of the gold foil experiment?
    12·1 answer
  • What is the most highly populated rotational level of Cl2 (i) 25deg C and (ii) 100 deg C? Take B=0.244cm-1.This question should
    10·1 answer
  • Based on electronegativity, select the molecule with the most ionic character. Group of answer choices SBr2 OBr2 SeCl2 TeI2 SCl2
    7·1 answer
  • Which type of stress causes rocks to fold?
    15·2 answers
  • In order for convection to transfer heat, particles need to
    7·2 answers
  • I what process does a solid change directly into a vapor​
    12·1 answer
  • When gravity is the only force acting on an object, the object is said to be in__.
    7·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!