Answer:
79 g
Explanation:
Density (d) of iron = 7.9 g/cm³
Volume of the iron (V) = 10 cm³
Mass of the iron (m) = ?
Solution:
Formula will be used
d = m/V
As we have to find mass so rearrange the above equation
m = dV . . . . . . . . . . . (1)
Put values in above equation 1
m = 7.9 g/cm³ x 10cm³
m = 79 g
So,
mass of iron = 79 g
Answer:
4Cr + 3O2 —> 2Cr2O3
Explanation:
Information from the question include:
Chromium + oxygen -> chromium(III) oxide
From the word equation given above, the equation can be written as follow:
Cr + O2 —> Cr2O3
The equation can be balance by doing the following:
There are 2 atoms of O on the left side and 3 atoms on the right side. It can be balance by putting 2 in front of Cr2O3 and 3 in front of O2 as shown below:
Cr + 3O2 —> 2Cr2O3
Now, we have 4 atoms of Cr on the right side and 1 atom on the left. It can be balance by putting 4 in front of Cr as shown below:
4Cr + 3O2 —> 2Cr2O3
Now the equation is balanced
One correct thging is that there are the same amount of positive and negative atoms
Answer:
8.55 × 10²⁴ Ions
Explanation:
Ammonium Chloride is an ionic compound which contains a monatomic anion (Cl⁻ ; Chloride) and a polyatomic cation (NH₄⁺ ; Ammonium).
Hence, when added in water Ammonium Chloride ionizes as;
NH₄Cl → NH₄⁺ + Cl⁻
Hence, we can say that it produces two ions when dissolved in water.
Also,
We know that 1 mole of any substance contains exactly 6.022 × 10²³ particles which is also called as Avogadro's Number. So in order to calculate the number of ions contained by 7.1 moles of NH₄Cl, we will use following relation to first calculate the number of molecules as;
Moles = Number of Molecules ÷ 6.022 × 10²³ Molecules.mol⁻¹
Solving for Number of Molecules,
Number of Molecules = Moles × 6.022 × 10²³ Molecules.mol⁻¹
Putting values,
Number of Molecules = 7.1 mol × 6.022 × 10²³
Number of Molecules = 4.27 × 10²⁴ Molecules
So,
As,
1 Molecule of NH₄Cl contained = 2 Ions
So,
4.27 × 10²⁴ Molecules of NH₄Cl will contain = X ions
Solving for X,
X = 2 Ions × 4.27 × 10²⁴ Molecules / 1 Molecule
X = 8.55 × 10²⁴ Ions
This statement is false due to the fact that the ammonia gas has the lower molar mass.
