Answer:
A balanced chemical equation must always include coefficients on every reactant and product.
Explanation:
<u>A balanced chemical equation does not need to include coefficients on every reactant and product.</u>
For example, below is a balanced chemical equation in which the reactants and the products have no coefficients whatsoever:
NaOH(aq) + HCl (aq) -----> NaCl (s) + H2O (l)
<em>Of course, a properly written chemical equation must include the states of matter of all the substances in the reaction and the number of atoms of each element must balance both in the reactant and product sides of the equation. Generally, a balanced chemical equation must obey the law of conservation of matter which opines that matter can neither be created nor destroyed but can only be converted from one form to another. </em>
Hence, that a balanced chemical equation must always include coefficients on every reactant and product is not true.
Answer: because the tablet is already crushed and is easy for the organism to absorb instead of having to break it down
Explanation:
Your instructor is probably expecting the answer B) III only.
III) The evolution or <em>absorption of heat</em> is evidence of a <em>chemical change</em>.
I) Boiling water and IV) mixing paint are <em>physical changes</em>.
II) A change in colour on mixing is usually an indication of a reaction (but not when mixing paint). However, in this case, the lighter blue colour might have happened simply because you are diluting the solution. You would have to do an experiment which is correct.
Answer:
92.8%
Explanation:
Step 1: Given data
- Mass of lead in the bullet (mPb): 11.6 g
- Mass of tin in the bullet (mSn): 0.5 g
- Mass of antimony in the bullet (mSb): 0.4 g
Step 2: Calculate the total mass of the bullet
The total mass of the bullet is equal to the sum of the masses of the elements that form it.
m = mPb + mSn + mSb = 11.6 g + 0.5 g + 0.4 g = 12.5 g
Step 3: Calculate the mass percentage of Pb in the bullet
We will use the following expression.
%Pb = mPb / m × 100%
%Pb = 11.6 g / 12.5 g × 100% = 92.8%
Answer:
Explanation:
PCl₅ ⇄ PCl₃ + Cl₂
1 mole 1 mole 1 mole
molecular weight of PCl₅ = 208.5
molecular weight of PCl₃ = 137.5
molecular weight of Cl₂ = 71
moles of PCl₅ = .0185
moles of PCl₃ = .0924
moles of Cl₂ = .1873
Total moles = .2982 moles
mole fraction of PCl₅ = .062
mole fraction of PCl₃ = .31
mole fraction of Cl₂ = .628
If total pressure be P
partial pressure of PCl₅ = .062 P
partial pressure of PCl₃ = .31 P
partial pressure of Cl₂ = .628 P
Kp = .31 P x .628 P / .062 P
= 3.14 P
To calculate Total pressure P
PV = nRT
P x 4 x 10⁻³ = .2982 x 8.31 x 600
P = 371.7 x 10³
= 3.717 x 10⁵ Pa
Kp = 3.14 P = 3.14 x 3.717 x 10⁵ Pa
= 11.67 x 10⁵ Pa
Kp = Kc x 
= 1
11.67 x 10⁵ = Kc x 
Kc = 234
