Answer:
Water does not remain when an insoluble substance is added
It begins with heating of phenol and formaldehyde in the presence of a catalyst such as hydrochloric acid, zinc chloride, or the base ammonia. This creates a liquid condensation product, referred to as Bakelite A, which is soluble in alcohol, acetone, or additional phenol.
Answer: 99.45 g
Explanation: we have 22.5 g of Platinum in every 1cm3 of Platinum so if we take 4.42 cm3 of Platinum we will have 4.42 × 22.5 g = 99.45 g of Platinum
Answer:
Chopping wood logs
A pot of water o a grate over a burning fire
Explanation:
Physical change is easily reversible. Burning/combustion is a chemical process where substances react rapidly with oxygen: this is usually irreversible.
The marshmallow, roasted food and burned wood all undergo combustion and hence are tagged chemical changes.
Explanation:
Answer:
4) 4Fe + 3O₂ → 2Fe₂O₃
Explanation:
4Fe + 3O₂ → 2Fe₂O₃
In this equation the numbers of atoms are same in both side. There are four iron and six oxygen atoms are present on left and right side of equation. That's why atoms are conserved. This equation completely followed the law of conservation of mass.
Law of conservation of mass:
According to the law of conservation mass, mass can neither be created nor destroyed in a chemical equation.
This law was given by french chemist Antoine Lavoisier in 1789. According to this law mass of reactant and mass of product must be equal, because masses are not created or destroyed in a chemical reaction.
