Molar mass
CaH₂ = 42.0 g/mol
H₂ = 2.0 g/mol
<span>Balanced chemical equation :
</span>CaH2 + 2 H₂O = Ca(OH)₂ + 2 H₂
42.0 g CaH₂ --------------------- 4.0 g H2
? g CaH₂ ---------------------- 4.550 g H2
mass = 4.550 * 42.0 / 4
mass = 191,1 / 4
mass =<span> 47.775 g of CaH₂</span>
<span>hope this helps!</span>
Answer:
Complex System
Explanation:
Given that, a descriptive scientific investigation is one of the three main types of investigation which formulates and quantify the natural phenomenon. This natural phenomenon oftentimes involves Complex System, such as microscopic organisms, thereby, scientists often make observations to understand the interacting parts of this COMPLEX SYSTEM
Hence, the right answer is a COMPLEX SYSTEM
Answer:
Explanation:
In all calorimetric experiment , the calorimeter must be isolated from the surrounding . Otherwise the heat change in the experiment can not be determined with precision .
The reaction is endothermic . Hence, there is lowering of temperature due to absorption of heat in the reaction equal to ΔH°. The value of ΔH° can be calculated by measuring fall in the temperature of the content . The fall in the temperature will be less when heat is allowed to come from the surrounding . Less fall of temperature will result in less ΔH° to be calculated .
Hence in the given experiment , if the student neglects to put lid on the cup , the experiment will give less value of ΔH°.
Answer:
Molecules make scents. Aromatic ones (That is, containing rings of carbon atoms with delocalised electrons). Some unpleasant smells are due to hydrogen and sulphur groups.
Explanation:
