Answer:
Explanation:
1) Chemical formula of sodium carbonate: <em>Na₂CO₃</em>
2) Ratio of carbon atoms:
- The number of atoms of C in the unit formula Na₂CO₃ is the subscript for the atom, which is 1 (since it is not written).
Hence, the ratio is 1 C atom / 1 Na₂CO₃ unit formula.
This is, there is 1 atom of carbon per each unit formula of sodium carbonate.
3) Calculate the number of moles in 1.773 × 10⁷ carbon atoms
- Divide by Avogadro's number: 6.022 × 10²³ atoms / mol
- number C moles = 1.773 × 10⁷ atoms / (6.022 × 10²³ atoms/mol)
- number C moles = 2.941 × 10⁻¹⁷ mol
Since, the ratio is 1: 1, the number of moles of sodium carbonate is the same number of moles of carbon atoms.
Answer:
balanced in ACID not BASE
Cr2O7^2-(aq) +3Hg(l) +14 H^1+ ----> 3Hg^2+ + 2Cr^3+(aq) + 7H2O
Answer
Cr2O7^2-(aq) +3Hg(l) +14 H^1+ ----> 3Hg^2+ + 2Cr^3+(aq) + 7H2O
Explanation:
Cr2O7^2-(aq) + Hg(l) ----> Hg^2+(aqH) + Cr^3+(aq)
add H^1+ (acid) to capture the O and make 7 water molecules
Cr2O7^2-(aq) + Hg(l) + H^1+ ----> Hg^2+(aqH) + Cr^3+(aq) + 7H2O
Cr goes from +6 to +3 by gaining 3 e
Hg goes from 0 to +2 by losing 2 e
we need 3 Hg for every 2 Cr
so
Cr2O7^2-(aq) +3Hg(l) +14 H^1+ ----> 3Hg^2+ + 2Cr^3+(aq) + 7H2O
2 Cr on the right and left
Net 12 positive charges on the right and the left
3 Hg on the right and left
14 H on the right and left
the equation is balanced
we cannot balance the equation in a basic solution with OH^1-
we have plenty of O in the dichromate ion. we need to convert it to water which take free H^1+ from the acid
Answer:
a. Moles of 
= 0.001643 moles
b. 0.296 g
c. 0.3098 g
d. Not acceptable
Explanation:
a.
Considering:
Or,
Given :
For :
Molarity = 0.1052 M
Volume = 15.62 mL
The conversion of mL to L is shown below:
1 mL = 10⁻³ L
Thus, volume = 15.62×10⁻³ L
Thus, moles of :
Moles of = 0.001643 moles
b.
The reaction of NaOH with the acetylsalicylic acid is in the ratio of 1:1.
Thus, Moles of NaOH = Moles of acetylsalicylic acid = 0.001643 moles
Molar mass of acetylsalicylic acid = 180.16 g/mol
The formula for the calculation of moles is shown below:
Thus,
Mass = Moles * Molar mass = 0.001643 moles * 180.16 g/mol = 0.296 g
c.
1.159 g of sample contains 0.296 g of acetylsalicylic acid
1.213 g of sample contains 
g of acetylsalicylic acid
Mass of acetylsalicylic acid = 0.3098 g = 309.8 mg
d. Sample contains = 309.8 mg
Manufacturer claiming = 315 mg to 335 mg
Thus , it is not acceptable.
Gain or lose.
The exchange of electrons in chemical bonding seeks to fulfill the octet rule. There are some exceptions, such as with hydrogen and helium, whose valence shells have a capacity of two electrons.
In order to emit electrons, the cesium will have to absorb photons. Each photon will knock out one electron by transferring its energy to the electron. Therefore, by the principle of energy conservation, the energy of the removed electron will be equal to the energy of the incident photon. That energy is calculated using Planck's equation:
E = hf
E = 6.63 x 10⁻³⁴ * 1 x 10¹⁵
E = 6.63 x 10⁻¹⁹ Joules
The electron will have 6.63 x 10⁻¹⁹ Joules of kinetic energy
