Quantitative data because it involves a number (quantity)
Answer:
The answer to your question is CuSO₄
Explanation:
To answer your question just remember the following information
- A chemical reaction is divided into sections
reactants and products
reactants on the left side of the reaction
products on the right side of the reaction
- All the symbols have a meaning
(s) means that that compound is in solid phase
(aq) means that that compound is dissolved in solution.
Then, the answer is CuSO₄
The chemical equation is missbalaced.
The right balanced chemical equation is:
<span>2NaHCO3(s) + 129 kJ ---> Na2CO3(s) + H2O(g) + CO2(g)
Then, now you know that 2 moles of NaHCO3 requires 129 kJ heat, and you just need to convert 25.5 grams of NaHCO3 into number of moles to calculare the amount of heat needed.
A) Number of moles in 25.5 g of NaHCO3, n:
n = grams / molar mass
molar mass NaHCO3 = 23 g/mol + 1g/mol + 12g/mol + 3*16g/mol = 84 g/mol
n = 25.5 g / 84 g/mol = 0.304 mol
B) Heat required
Make the proportion with the theoretical ratio:
2mol / 129 kJ = 0.304 mol / x
=> x = 0.304 mol * 129 kJ / 2 mol = 19.608 kJ
Answer: 19.6 kJ
</span>
Index fossils<span> can be </span>used<span> to help determine the relative age of </span>rock<span> layers. </span>Index fossils<span> are from species that only existed for a short time. </span>Index fossils<span> are found in</span>rock<span> layers. Trilobites and Graptolites are </span><span>index fossils.</span>
