Answer:false
Explanation:matter cannot be created or destroyed in a chemical reaction it is rearranged
Answer:
0.125 mole
Explanation:
From Avogadro's hypothesis, we discovered that 1 mole of any substance contains 6.02x10^23 atoms.
The statement above suggests that 1 mole of chromium contains 6.02x10^23 atoms.
Now, if 1mole of of chromium contains 6.02x10^23 atoms,
Then Xmol of chromium contains 7.52x10^22 atoms i.e
Xmol of chromium = 7.52x10^22/6.02x10^23
Xmol of chromium = 0.125 mole
Therefore, 0.125 mole of chromium contains 7.52x10^22 atoms
Answer:
Explanation:
The covalent bond is the chemical bond between atoms where electrons are shared, forming a molecule. Covalent bonds are established between non-metallic elements, such as hydrogen H, oxygen O and chlorine Cl. These elements have many electrons in their outermost level (valence electrons) and have a tendency to gain electrons to acquire the stability of the electronic structure of noble gas.
The covalent bond between two atoms can be polar or nonpolar. If the atoms are equal, the bond will be nonpolar (since no atom attracts electrons more strongly). But, if the atoms are different, the bond will be polarized towards the most electronegative atom, because it will be the atom that attracts the electron pair with more force. Then it will be polar.
It can occur in a molecule that the bonds are polar and the molecule is nonpolar. This occurs because of the geometry of the molecule, which causes them to cancel the different equal polar bonds of the molecule.
In carbon tetrachloride the bonds are polar, but the tetrahedral geometry of the molecule causes all four dipoles to cancel out and the molecule to be apolar.
Answer:
True
Explanation:
Molecular mass of 
:
Molecular mass of Ca + molevular mass of C + molecular mass of O × 3
40g + 12g + 16 × 3g
= 40g + 60 = 100g
Thus its true
Answer:
The final concentration is 0.288 M (approximately)
Explanation:
Using dilution formula:
C1V1 = C2V2
Where C1 is the initial concentration
C2 is the final concentration
V1 is the initial volume
V2 is the final volume
In the first dilution, C1 = 1.8M,
V1 =71mL, V2 = 218mL from the formula C2 = 1.8 ×71/281
=0.5862M
In the second dilution,
C1 = 0.5862M, V1 = 109mL, V2 = 222 mL (109+113)
C2 = 0.5862 × 109 ÷ 222
= 0.288 M (approximately) assuming volume is additive.
