<u>Answer:</u>
<em>B. A and B</em>
<em></em>
<u>Explanation:</u>
1. Solids have a definite volume, definite size and definite shape
2. The particles present in a solid are very closely packed since the intermolecular forces between them are very strong. The molecules do not move apart.
3. Melting point is the temperature at which solid changes into a liquid.
4. When a solid is heated to the melting point the intermolecular forces are overcome by the energy and the molecules present in it moves from its fixed position to take its liquid state which is called as melting.
Answer:
See Explanation
Explanation:
The Law of Conservation of Matter as applied to chemical reactions says that matter is neither created nor distroyed, only changed in form. This implies that the mass of substances going into a reaction process must equal the mass of products generated during the reaction process.
Empirically,
∑ mass reactants = ∑ mass products
One can test this idea after balancing a chemical equation by determining the sum of formula weights of reactants and products; then compare. If reaction was properly balanced, the total mass reactants = total mass of products.
Example:
Combustion of Methane => CH₄(g) + 2O₂(g) => CO₂(g) + 2H₂O(l)
Equation Weights => 16amu + 64amu <=> 44amu + 36amu
Mass Reactants = Mass Products => 80amu <=> 80amu.
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*amu = atomic mass units => sum of atomic weights of elements
Answer:
Q = 270 Joules (2 sig. figs. as based on temperature change.)
Explanation:
Heat Transfer Equation of pure condensed phase substance => Q = mcΔT
Mixed phase (s ⇄ l melting/freezing, or l ⇄ g boiling/condensation) heat transfer equation => Q = m∙ΔHₓ; ΔHₓ = phase transition constant
Since this is a pure condensed phase (or, single phase) form of lead (Pb°(s)) and not melting/freezing or boiling/condensation, one should use
Q = m·c·ΔT
m = mass of lead = 35.0g
c = specific heat of lead = 0.16J/g°C
ΔT = Temp change = 74°C - 25°C = 49°C
Q = (35.0g)(0.16J/g·°C )(49°C) = 274.4 Joules ≅ 270 Joules (2 sig. figs. as based on temperature change.)
The reaction of HCl and NaOH is HCl + NaOH = NaCl + H2O. So the mole number of HCl and NaOH is equal. So the volume of HCl =0.01*0.1/0.02=0.05 L =50 ml. So the answer is D).
Answer:
An Element is a substance made up of only one type of atom as like gold, copper, oxygen, etc.
Copper sulphate with molecular formula 
, the elements are copper, sulphur and oxygen. It is formed by combination of 
cation and 
anion.
Copper sulphide with molecular formula 
, the elements are copper and sulphur. It is formed by combination of cation and 
anion.
