<h2>The grams of the excess reactant that are left at the end of reaction is</h2><h2>= 1.2014 grams</h2>
<h3>calculation</h3>
find the moles of each reactant
moles = mass/molar mass
molar mass of Ga= 69.7 g/mol
molar mass of As= 74.9 g/mol
mole of Ga = 4 g÷69.7 g/mol=0.05739 moles
moles of As=5.50 g÷74.9 g/mol =0.07343 moles
0.05739 moles of Ga reacted completely with 0.05739 moles of As therefore As was in excess
Therefore the moles of As that did not react = 0.07343 - 0.05739=0.01604 moles
mass that did not react = moles that was left x molar mass of As
that is; 0.01604 x 74.9=1.2014 grams
The given dehydration equation is,
Cadmiumnitrate tetrahydrate when heated dehydrates releasing the combined water as water vapor. The reaction produces 4 moles of gaseous product water vapor. So, the degree of disorder or randomness increases. Hence, the sign of change in entropy is positive.
This reaction is spontaneous at room temperature even if it is endothermic as the sign of change in entropy is positive.
Answer:
a. 0.73
Explanation:
Given data
- Change in the temperature (ΔT): 3.0°C
- Mass of the metal (m): 17.5 g
- Specific heat of the metal (c): ?
We can determine the specific heat of the metal using the following expression.
Q = c × m × ΔT
c = Q / m × ΔT
c = 38.5 J / 17.5 g × 3.0°C
c = 0.73 J/g.°C
Answer:
Atomic number = 10
Mass number = 20
Explanation:
Mass number = neutrons+protons
Mass number = 10+10 = 20
Answer:
The symbol is the right answer.
Explanation:
The “ Symbol” is the correct answer because chemist uses the letters of the alphabet to denote the element. For instance, the element oxygen is denoted by the letter of the alphabet “O”, the hydrogen is denoted by the letter of alphabet “H”, Boron is denoted by the letter of alphabet “B”, etc. Here these are the examples that use one letter but there are other elements that use more than 1 letter as the symbol. For example, the Chlorine is represented by the Cl.
