Answer:
-12162.47 joules (or -12000 joules when accounting for significant figures)
Explanation (btw I used 1 cal as 4.184 joules because SI units are better):
q = m c delta T
q = (70.9) (4.184) (25 - 66)
q = (70.9) (4.184) (-41)
q = -12162.47 joules
Answer: 
Explanation:
Alpha Decay: In this process, a heavier nuclei decays into lighter nuclei by releasing alpha particle. The mass number is reduced by 4 units and atomic number is reduced by 2 units.
General representation of an element is given as: 
where,
Z represents Atomic number
A represents Mass number
X represents the symbol of an element
General representation of alpha decay :
The balanced nuclear equation when the isotope Strontium-90 decays by Q- decay is :
Atoms of oxygen are electronegative and attract the shared electrons in their covalent bonds.
Answer:
40 moles of O₂
30 moles of CO₂
Explanation:
Given parameters:
Number of moles of C₃H₄ = 10moles
Unknown:
Number of moles of CO₂ = ?
Solution:
The number of moles helps to understand and make quantitative measurements involving chemical reactions.
We start by solving this sort of problem by ensuring that the given equation is properly balanced;
C₃H₄ + 4O₂ → 3CO₂ + 2H₂O
We can clearly see that all the atoms are conserved.
Now, we work from the known to unknown. We know the number of moles of C₃H₄ to be 10moles;
1 mole of C₃H₄ reacted with 4 moles of O₂
10 moles of C₃H₄ will react with 10 x 4 = 40moles of O₂
1 mole of C₃H₄ will produce 3 moles of CO₂
10 moles of C₃H₄ will produce 10 x 3 = 30moles of CO₂
