Answer:
a) 
2 moles of Zinc sulphide in solid form reacts with 3 moles of Oxygen in gaseous form to give 2 moles of Zinc oxide in solid form and 2 moles of sulphur dioxide in gaseous form.
b) 
1 mole of calcium hydride in solid form reacts with 2 moles of liquid water to give 1 mole of calcium hydroxide dissolved in water and 2 moles of hydrogen in gaseous form.
The chemical reactions are written by writing the chemical formula of the reactants on left side of the arrow followed by chemical formula of the products. The number of atoms of each element must be balanced to follow the law of conservation of mass.
Answer:
Explanation:
exothermic reactions involve release of heat whereas endothermic reaction involve absorption of heat.
Oxygen had 6 valence electrons
Answer:
The area of the given rectangular index card = <u>9677.4 mm²</u>
Explanation:
Area is defined as the space occupied by a two dimensional shape or object. The SI unit of area is square metre (m²).
<u>The area of a rectangle</u> (A) = length (l) × width (w)
Given dimensions of the rectangle: Length (l) = 5.0 inch, Width (w) = 3.0 inch
Since, 1 inch = 25.4 millimetres (mm)
Therefore, l = 5 × 25.4 = 127 mm, and w = 3 × 25.4 = 76.2 mm
Therefore, <u>the area of the given rectangular index card</u> = A= l × w = 127 mm × 76.2 mm = <u>9677.4 mm²</u>
Answer:
10 molecules of NH₃.
Explanation:
N₂ + 3H₂ --> 2NH₃
As the N₂ supply is unlimited, what we need to do to solve this problem is <u>convert molecules of H₂ into molecules of NH₃</u>. To do so we use the <em>stoichiometric coefficients</em> of the balanced reaction:
- 15 molecules H₂ *
= 10 molecules NH₃
10 NH₃ molecules could be prepared from 15 molecules of H₂ and unlimited N₂.
