Answer:
Independent: sizes of nails
Dependent: number of paper clips
Controlled: Battery, wire and type of nails
Explanation:
An independent variable is a variable which when changes does not the effect the results of the experiment. It does not depends upon the dependent variable.
A dependent variable is defined as a variable which is affected when the independent variable is changed by the researcher or the experimenter. It depends greatly upon the independent variable.
While a controlled variable is that variable whose value is not changed in an experiment. It contains all the constants.
In the context,
the independent variable are : sizes of nails
the dependent variables are : number of paper clips
the Controlled variables are: Battery, wire and type of nails
Answer:
3.64g
Explanation:
Given parameters:
Mass of NH₃ = 18.1g
Mass of Cu₂O = 90.4g
Unknown:
Limiting reactant = ?
Mass of N₂ formed = ?
Solution:
The reaction equation is given as:
Cu₂O + 2NH₃ → 6Cu + N₂ + 3H₂O
The limiting reactant is the one in short supply in the reaction. Let us find the number of moles of the given species;
Number of moles =
Molar mass of Cu₂O = 2(63.6) + 16 = 143.2g/mol
Molar mass of NH₃ = 14 + 3(1) = 17g/mol
Number of moles of Cu₂O =
= 0.13moles
Number of moles of NH₃ =
= 5.32moles
From this reaction;
1 mole of Cu₂O combines with 2 mole of NH₃
So 0.13moles of Cu₂O will combine with 0.13 x 2 mole of NH₃
= 0.26moles of NH₃
Therefore, Cu₂O is the limiting reactant. Ammonia is in excess;
Mass of N₂;
Mass = number of moles x molar mass
1 mole of Cu₂O will produce 1 mole of N₂
0.13 mole of Cu₂O will produce 0.13 mole of N₂
Mass = 0.13 x (2 x 14) = 3.64g
C) Thermal energy. Your body turns the mechanical energy into thermal energy.
Answer: 22g of chlorine would be needed to carry out this synthesis reaction
Explanation:
A synthesis reaction is one in which two or more than two elements combine together to forma single product.

The atoms present in the reactants are found on the product side. According to the law of conservation of mass, the number of atoms on both sides of the arrow must be same as the total mass must be conserved.
15 grams of sodium reacts with 22 grams of chlorine to yield 37 grams of sodium chloride. Thus 22g of chlorine would be needed to carry out this synthesis reaction.
Almost all properties are common to elements within a single group on the periodic table. They react with water in the same way, they have the same number of valence electrons thereby having the same valency, the number of shells in the atom of the element increases by one as we move down the group.
In general, they have the same chemical properties as chemical properties depend on the number of electrons in the valence shell i.e. the outermost shell in the atom of an element.