Answer:
C₅H₁₀O₄
Explanation:
The empirical formula is the simplest whole-number ratio of atoms in a compound.
The ratio of atoms is the same as the ratio of moles.
So, our job is to calculate the molar ratio of C:H:O.
Assume 100 g of deoxyribose.
1. Calculate the mass of each element.
Then we have 44.8 g C, 7.5 g H, and 47.7 g O.
2. Calculate the moles of each element
3. Calculate the molar ratio of the elements
Divide each number by the smallest number of moles
C:H:O = 3.730:7.44:2.981 = 1.251:2.50:1 = 5.005:9.98:4 ≈ 5:10:4
4. Write the empirical formula
EF = C₅H₁₀O₄
Explanation:
Atomic mass means the sum of total number of protons and neutrons present in an atom.
When an atom is neutral then number of protons equal the number of electrons.
Mass of a proton equals to 1.007276 u, mass of neutron equals to 1.008664 u.
For example, in a 
atom there are total 9 protons and number of neutrons is 19 - 9 = 10.
Since, it is a neutral atom so number of electrons will also be 9.
So, total mass will be calculated as follows.
Total mass = 9 (mass of electron + mass of proton)
= 9 (1.007825 u)
= 9.07043 u
Therefore, we can conclude that total mass of protons and electrons in is 9.07043 u.
Answer:
c) Hexagonal close packed
Explanation:
The fact that a material is crystalline, amorphous or semicrystalline defines some of its properties. For example, if a material had the option of being crystalline or amorphous, it would be observed that in the crystalline state the density of the material would be greater in the amorphous state. This is because because of the order that the atoms follow in the crystalline material, it is possible to place more atoms in the same physical volume. When there are more atoms there is more mass in the same volume so the density is higher than when the material is amorphous.
The different crystalline structures are the following:
Simple cubic structures: the unit cell is a common edge cube, with a defined network point in each of its vertices.
Cubic structure centered on the body: the unit cell is a cube with a common edge. It has a defined network point in each of its vertices and a defined network point in the geometric center of the cube. INCLUDES a)
Cubic structure centered on the face: the unit cell is a cube with a common edge. It has a defined network point in each of its vertices and a defined network point in the geometric center of each of its faces. INCLUDES b) and d)
Answer:
The volume of the gas at given temperature is 
Explanation:
= initial pressure of gas = 1 atm
= initial temperature of gas = 
= initial volume of gas = 
(
, 1 mL = 0.001 L)
..[1]
= final pressure of gas = 2.1 atm
= final temperature of gas = 
= final volume of gas = ?
..[2]
By dividing [1] and [2] we get combined gas equation :,
Now put all the given values in the above equation, we get:
The volume of the gas at given temperature is
Answer:
Option 4. There's no hydrogen bonding between HBr molecules at all.
Explanation:
<h3>SiH₄</h3>
SiH₄ molecules are tetrahedral and symmetric. Dipoles due to the polar Si-H bonds balance each other. SiH₄ molecules are nonpolar. Only instantaneous dipoles are possible between those molecules.
<h3>C₆H₆ Benzene</h3>
Similar to SiH₄, benzene is symmetric. Dipoles due to the weakly polar C-H bonds balance each other. Benzene molecules are nonpolar. Only instantaneous dipoles are possible between those molecules.
<h3>NH₃</h3>
There are two conditions for hydrogen bonding to take place:
- H atoms are directly bonded to a highly electronegative element: Nitrogen, Oxygen, or Fluorine.
- There is at least one lone pair of electrons nearby.
Consider the Lewis structure of NH₃. There are three H atoms in each NH₃ molecule. Each of the three H atoms is bonded directly to the N atom with a highly polar N-H bond. Also, there is a lone pair of electrons on the N atom. Hydrogen bonding will take place between NH₃ molecules.
NH₃ is a relatively small molecule. As a result, hydrogen bonding will be the dominant type of intermolecular force between NH₃ molecules.
<h3>HBr</h3>
There are three lone pairs on the Br atom in each HBr molecule. However, no H atom is connected to any one of the three highly electronegative elements: N, O, or F. The Br atom isn't electronegative enough for the H atom to form hydrogen bonding. HBr molecules are polar. As a result, the dominant type of intermolecular forces between HBr molecules will be dipole-dipole interactions (A.k.a. permanent dipole.)
<h3>CaO</h3>
Calcium is a group 2 metal. Oxygen is one of the three most electronegative nonmetal. (Again, the most electronegative elements are: Nitrogen, Oxygen, and Fluorine.) As a main group metal, Ca atoms tend to lose electrons and form positive ions. Oxygen will gain those electrons to form a negative ion. As a result, CaO will be an ionic compound full of Ca²⁺ and O²⁻ ions. Forces between ions with opposite charges are called ionic bonds.
