Answer:
a solution color becoming less intense due to dilution- is not an evidence of a chemical reaction
bubbles (gas formation) - evidence of a chemical reaction
explosion or fire - evidence of a chemical reaction
changes in color- evidence of a chemical reaction
precipitation- evidence of a chemical reaction
changes in temperature - evidence of a chemical reaction
a solid liquifying - is not an evidence of a chemical reaction
solution colors mixing - is not an evidence of a chemical reaction
Explanation:
A chemical change is not easily reversible and yields new substances. It is often accompanied by a loss or gain of heat.
In the answer section, i have shown some evidences that lead us to conclude that a chemical reaction has taken place. The occurrence of a chemical change often goes with the formation of new substances as earlier stated and any of these signs may accompany the process.
For instance, when a metal is dropped in dilute acid solution, bubble of hydrogen gas indicates that a chemical reaction has taken place.
<h3>
Answer:</h3>
2C₂H₆ + 7O₂ → 4CO₂ + 6H₂O
<h3>
Explanation:</h3>
- The equation for the reaction shown represents the combustion of ethane.
C₂H₆ + O₂ → CO₂ + H₂O
- To balance the equation we put the coefficients, 2, 7, 4, and 6 on the reactants and products.
2C₂H₆ + 7O₂ → 4CO₂ + 6H₂O
- Balancing chemical equations makes the number of atoms of each element equal on both side of the equation.
- It ensures that chemical equations obey the law of conservation of mass in chemical reactions.
Answer: 8.3 moles
Explanation:
Number of moles of lithium = ?
Mass in grams = 25 grams
Molar mass of lithium = 3g/mol
Recall that:
Number of moles = (Mass in grams / Molar mass)
Number of moles = 25 grams / 3g/mol
= 8.3 moles
Thus, there are 8.3 moles of lithium in 25 grams of lithium
<span><span>When the solvent disrupts the solvents ability to form that crystal lattice and thus need lower temperatures (freezing point depression) than normally expected to form the solid. </span>
My guess would be: B. The solute disrupts crystals formation by the solvent
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Answer:
HNO2
Explanation:
Because H2CO3 is a weak acid in CH3COOH