Hey there!:
Molar mass Ca(NO2)2 = 132.089 g/mol
Mass of solute = 120 g
Number of moles:
n = mass of solute / molar mass
n = 120 / 132.089
n = 0.0009084 moles of Ca(NO2)2
Volume in liters of solution :
240 mL / 1000 => 0.24 L
Therefore:
Molarity = number of moles / volume of solution
Molarity = 0.0009084 / 0.24
Molarity = 0.003785 M
Hope that helps!
the balanced chemical equation for decomposition of HgO is as follows
2HgO --> 2Hg + O₂
stoichiometry of HgO to O₂ is 2:1
number of HgO moles heated are - 3.00 g / 216.59 g/mol = 0.0139 mol
according to stoichiometry of reaction -
number of O₂ moles formed = 0.0139 mol/ 2 = 0.00695 mol
mass of O₂ to be formed - 0.00695 mol x 32.00 g/mol = 0.2224 g
but the actual yield = 0.195 g
percent yield = actual yield / theoretical yield x 100 %
percent yield = 0.195 g / 0.2224 g x 100 % = 87.7 %
answer is 87.7 %
Given:
Mass of methanol, m = 18754 kg
Density of methanol, ρ = 0.788 g/cm³
By definition, the volume of methanol in the collection tank is
Volume = mass/density
Answer: 2.38 x 10⁷ g/cm³
Answer : Chemicals A and B form an endothermic reaction, and chemicals C and D form an exothermic reaction.
Explanation :
Endothermic reaction : When the system absorb heat from the surrounding then the surrounding become cool.
Exothermic reaction : when the system releases heat into the surrounding then the surrounding become hot.
According to the question,
when we mixed chemical A and chemical B together in a test tube to form chemical C, the mixture become cool. This means that the system is absorbing heat from the surrounding and thus the reaction is called a endothermic reaction.
And when we added chemical D in chemical C, the new mixture becomes hot and explodes. This means that the system is releasing heat into the surrounding and thus the reaction is called as exothermic reaction.
Hey there:
1 cm³ = 1 mL
D = m / V
7.25 = 12.9 / V
V = 12.9 / 7.25
V = 1.779 cm³
