Chemical Formulae, Equations, Calculations
1. A student wanted to make 15.0 g of zinc chloride. The equation for the reaction is:
ZnCO3 + 2HCl → ZnCl2 + CO2 + H2O
What mass of zinc carbonate should the student add to the hydrochloric acid to make 15.0 g of zinc chloride?
[Ar of C = 12; Zn = 65; O= 16; Cl = 35.5; H= 1]
Ai এর মাধ্যমে
১০ লক্ষ+ প্রশ্ন ডাটাবেজ
প্র্যাকটিস এর মাধ্যমে নিজেকে তৈরি করে ফেলো
উত্তর দিবে তোমার বই থেকে ও তোমার মত করে।
সারা দেশের শিক্ষার্থীদের মধ্যে নিজের অবস্থান যাচাই
A second piece of magnesium ribbon is ignited and placed in a gas jar of carbon dioxide. A very exothermic reaction occurs, forming magnesium oxide and carbon.
i) State what is meant by the term exothermic.
(1)
ii) Give the chemical equation for this reaction.
(1)
iii) A fire starts in a warehouse where magnesium is stored. Suggest why it would not be suitable to use a carbon dioxide fire extinguisher to put out this fire.
(1)
This question has 4 part(s).
This question has 3 part(s).
Another organic compound has the percentage composition by mass
C = 38.7% H = 9.7% O = 51.6%
i) Calculate the empirical formula of this compound.
(3)
empirical formula = ..............................................................
ii) The relative molecular mass (Mr) of the compound is 62 Determine the molecular formula of the compound.
(2)
molecular formula = ........................................................
