Explanation:
mass = moles * molar mass
molar mass of carbon dioxide (CO2) = 12+32 = 44
= 19.5* 44 = 858
proof
moles = mass /molar mass
= 858/44 = 19.5 moles
Hydrogen bonds<span> hold the paired nitrogenous bases together. Because </span>hydrogen bonds<span> are weak </span>bonds<span>, the two strands of </span>DNA<span> are easily separated a characteristic that is important to </span>DNA's<span> function.</span>Hydrogen bonds<span> form between adenine and thymine and between cytosine and guanine.</span>
To make sure no cracks are in the crucible and also to remove any moisture present in the crucible by the process of heating.
B. Soft metals.. almost like clay
<h3><u>Answer;</u></h3>
Ethane (C2H6) is the excess reactant
<h3><u>Explanation;</u></h3>
From the equation;
2C2H6 + 7 O2 → 4CO2 + 6 H2O
2 moles of ethane requires 7 moles of oxygen to produce 4 moles of CO2 and 6 moles of water.
The mole ratio of ethane : oxygen is 2 : 7
10 g of C2H6 = 10/30 g/mol = 0.333 moles
12.5 g of Oxygen = 42.5/32 g/mol = 1.328 moles
Using C2H6 as limiting; 0.333 moles pf C2H6 requires 0.333× 7 =2.331 moles of oxygen
Using oxygen as limiting; 1.328 moles of oxygen requires, 1.328/7 = 0.1897 moles of ethane.
Therefore; Ethane is the excess reactant by 0.333 - 0.1897 = 0.1433 moles
