Answer: Fireworks exploding is a chemical change.
Explanation: Lighting gunpowder, and making the explosion is a chemical change.
Answer:
Mass = 121 g
Explanation:
Given data:
Mass in gram of CO₂ = ?
Volume = 61.8 L
Pressure = standard = 1 atm
Temperature = 273.15 K
Solution:
Formula:
PV = nRT
P= Pressure
V = volume
n = number of moles
R = general gas constant = 0.0821 atm.L/ mol.K
T = temperature in kelvin
1 atm × 61.8 L = n ×0.0821 atm.L/ mol.K × 273.15 k
61.8 L.atm = 22.42 atm.L/ mol × n
n = 61.8 L.atm /22.42 atm.L/ mol
n = 2.76 mol
Mass in gram:
Mass = number of moles × molar mass
Mass = 2.76 mol × 44 g/mol
Mass = 121 g
Answer:
The rate of disappearance of C₂H₆O = 2.46 mol/min
Explanation:
The equation of the reaction is given below:
2 K₂Cr₂O₇ + 8 H₂SO₄ + 3 C₂H₆O → 2 Cr₂(SO₄)₃ + 2 K₂SO₄ + 11 H₂O
From the equation of the reaction, 3 moles of C₂H₆O is used when 2 moles of Cr₂(SO₄)₃ are produced, therefore, the mole ratio of C₂H₆O to Cr₂(SO₄)₃ is 3:2.
The rate of appearance of Cr₂(SO₄)₃ in that particular moment is given 1.64 mol/min. This would than means that C₂H₆O must be used up at a rate which is approximately equal to their mole ratios. Thus, the rate of of the disappearance of C₂H₆O can be calculated from the mole ratio of Cr₂(SO₄)₃ and C₂H₆O.
Rate of disappearance of C₂H₆O = 1.64 mol/min of Cr₂(SO₄)₃ * 3 moles of C₂H₆O / 2 moles of Cr₂(SO₄)₃
Rate of disappearance of C₂H₆O = 2.46 mol/min of C₂H₆O
Therefore, the rate of disappearance of C₂H₆O = 2.46 mol/min
- Light energy from sun is converted into electrical energy in a solar cell.
- Electrical energy is stored as chemical energy in the solar cell.
- Chemical energy is converted back into electrical energy at night.
- Electrical energy is converted into light energy from the street lamp.
Answer: The reactants are baking soda and vinegar. Baking soda is a white powder, and vinegar is a clear liquid. The products of this reaction are carbon dioxide, water, and sodium acetate. Carbon dioxide is a colorless gas, water is a colorless liquid, and sodium acetate is a white crystalline powder.
A chemical change can be seen in how the molecular formulas of the products are different from the reactants, since the reactants have chemically changed into completely different molecules.
Hope this helps
