<h2>9. Given : P + O2 = P2O5</h2>
Balanced Chemical Equation: <u>4</u>P + <u>5</u>O2 = <u>2</u>P2O5
<u>Reactant Product</u>
P = (1) 4 | P = (2) 4
O = (2) 10 | O = (5) 10
Reaction Information
Phosphorus + Dioxygen = <u>Phosphorus Pentoxide</u>
Reaction Type: <u>Synthesis</u>
<h2>
10. Given: HCl + NaOH = NaCl + H2O </h2>
<u>Reactant Product</u>
H = 2 | H = 2
Cl = 1 | Cl = 1
Na = 1 | Na = 1
O = 1 | O = 1
<h3>
Chemical Equation is already in balance.</h3>
Reaction Information<em>:</em><em> </em><em>Hydrogen Chloride </em>+ <em>Sodium Hydroxide</em> = <em>Sodium Chloride </em>+ <em>Water</em>
Reaction Type<u> </u><u>:</u><u> </u><u>Double Displacement (Acid-Base)</u>
<h3>For more info:</h3>
<u>How to balance chemical equation?</u>
brainly.com/question/15939935
Answer : The mass of helium added to the cylinder was, 1.5 grams
Explanation :
Avogadro's law : It is defined as the volume of gas is directly proportional to the number of moles of gas at constant pressure and temperature.

or,

where,
= initial volume of gas = 2.00 L
= final volume of gas = 3.50 L
= initial moles of gas = 
= final temperature of gas = ?
Now put all the given values in the above equation, we get:


Now we have to calculate the mass of helium were added to the cylinder.


Mass of helium added = 3.5 - 2.00 = 1.5 g
Thus, the mass of helium added to the cylinder was, 1.5 grams
Answer: 2.5g
Explanation:
5 % sucrose solution means that 5 % of the weight of the solution is sucrose.
If 1 liter of water weighs 1000 grams. To prepare 5% sucrose solution 5/100 x 1000 = 50 grams. Since 1 liter equals 1000ml, thus a 5 % solution has 50 grams of solute dissolved in one liter.
To prepare 5% sucrose solution in 50mls
=5/100 x 50
= 0.05 x 50
= 2.5g
Therefore to prepare 5% sucrose solution in 50mls we dissolve 2.5g of sucrose in 50ml of water
<span>The electrical charge of the hydrogen atom is thought to be exactly zero. This is a consequence of the apparent equality of the magnitude of the electrical charges of the electron and the proton, and their opposite sign.</span>
A suspension is the mixture with the largest particles.