Answer:
The products have a higher heat content than the reactants.
Explanation:
The statement above is not true for an exothermic reaction because in an exothermic reaction heat is released to the surroundings. This simply means that the total energy of the products is less than that of the reactants.
Answer:

Explanation:
Atomic number : It is defined as the number of electrons or number of protons present in a neutral atom.
However, when we talk about the atomic number of the ion, it is not equal to the number of electrons as electron can be gained or loosed.
This is why, more appropriately, the number of the protons which are present in the nucleus of the atom is called the atomic number.
Thus, atomic number of phosphorus = 15
Mass number is the number of the entities present in the nucleus which is the equal to the sum of the number of protons and electrons.
Given, Mass number = 32
Thus, the symbol of the isotope is:-

Answer:
1.55 × 10²⁵ atoms of H
Explanation:
3.21mol C₃H₈ × 8mol H × (6.022×10²³)
Answer:
2NaOH + CO2 -> Na2CO3 + H2O
1) Find the moles of each substance

2) Determine the limitting reagent

∴ Carbon dioxide is limitting as it has a smaller value.
3) multiply the limiting reagent by the mole ratio of unknown over known
n(H2O ) = 0.3976369007 × 1/2
= 0.1988184504 moles
4) Multiply the number of moles by the molar mass of the substance.
m = 0.1988184504 × (1.008 × 2 + 16.00)
= 0.1988184504 × 18.016
= 3.581913202 g
Explanation:
Answer:
a. HCl.
b. 0.057 g.
c. 1.69 g.
d. 77 %.
Explanation:
Hello!
In this case, since the reaction between magnesium and hydrochloric acid is:

Whereas there is 1:2 mole ratio between them.
a) Here, we can identify the limiting reactant as that yielded the fewest moles of hydrogen gas product via the 1:1 and 2:1 mole ratios:

Thus, since hydrochloric yields fewer moles of hydrogen than magnesium, we realize it is the limiting reactant.
b) Here, we use the molar mass of gaseous hydrogen (2.02 g/mol) to compute the mass:

c) Here, we compute the mass of magnesium associated with the yielded 0.0248 moles of hydrogen:

Thus, the mass of excess magnesium turns out:

d) Finally, we compute the percent yield, considering 0.044 g is the actual yield and 0.057 g the theoretical yield:

Best regards!