Answer:
0.025 moles of NO₂ will produced
Explanation:
Given data:
Moles of NO₂ formed = ?
Volume of HNO₃ = 25.0 mL
Molarity of HNO₃ = 2 M
Solution:
Chemical equation:
Cu + 4HNO₃ → Cu(NO₃)₂ + 2NO₂ + 2H₂O
Number of moles of HNO₃:
Molarity = number of moles / volume in L
2M = number of moles / 0.025 L
Number of moles = 2 M × 0.025 L
Number of moles = 0.05 mol
Now we will compare the moles of HNO₃ with NO₂ from balance chemical equation.
HNO₃ : NO₂
4 : 2
0.05 : 2/4×0.05 =0.025
0.025 moles of NO₂ will produced.
Answer: C) The mass stays constant as it changed from a liquid to a gas
Explanation: Mass stays constant, it's never destroyed or created. It follows the law of conservation of mass.
It's 1. Melting a substance. The rest are chemical changes
The breakdown of mass percentage of the elements is determined by dividing molar masses to the total molar mass of the compound (246.37 g/mol). There are four elements: for Mg: 9.87%, S:13.01%, H:5.69%, 71.44%.
