Hello!
The observation that would provide the best evidence that a chemical reaction occurred is that The baking soda and hydrochloric acid combined, and bubbles formed.
When baking soda (NaHCO₃) and Hydrochloric Acid (HCl) combine, the following reaction happens:
NaHCO₃ + HCl → NaCl + H₂O + CO₂(g)↑
The gaseous Carbon Dioxide (CO₂) generated in this reaction is the responsible for the bubbles. The releasing of this gas is an evidence that a chemical reaction occurred between NaHCO₃ and HCl.
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Answer: m= 85.8 g CH2O
Explanation: First step is convert the molecules of CH2O to moles using the Avogadro's Number.
1.72x10²⁴ molecules CH2O x 1 mole CH2O / 6.022x10²³ molecules CH2O
= 2.86 moles CH2O
Next is convert the moles of CH2O to mass using the molar mass of CH2O
2.86 moles CH2O x 30 g CH2O / 1 mole CH2O
= 85.8 g CH2O
Sodium chloride (NaCl), whose only changes about 5g/100mL water over that entire range 100°C)
Answer:
B
Explanation:
Acid rain
damaging a marble statue or anything else
is a physical change. <3
A form of
electricity which can attract things is static electricity. Static electricity
is the result of an imbalance between negative and positive charges in an
object. These charges built up o the surface of an object until they find a way
to e released or discharged causing the attraction of things.
