Answer:
That unknown substance is water
Explanation:
Respiring while swimming underwater
Because anaerobic respiration means respiration with no oxygen, and there is no oxygen underwater
Answer:
Yes, but it must be kept at that value and do not let it to decrease more.
Explanation:
Hello.
In this case, in order to substantiate whether the cabin meet the federal standards, we need to convert the 500 mmHg to atm and compare the result with 0.72 atm by knowing that 1 atm equals 760 mmHg:

Thus, since 0.66 atm is 0.06 atm away from the federal standard we can infer that it may meet the federal standard, however, it would not be recommended to let the pressure decrease more than that.
Answer:
2 CrO42- + 3N2O + 10 H+ -----> 2Cr3+ + 6NO + 5H2O
Explanation:
2 CrO42- + 3N2O + 10 H+ -----> 2Cr3+ + 6NO + 5H2O
Oxidizing agent: -----------------------------> CrO42-
Reducing agent: ----------------------------> N2O
explanation:
in CrO4-2 oxdiation state of Cr = +6
in Cr+3 oxidation state = +3
+6 oxidation state changed from +3 it is reduction .
so CrO4-2 is oxidizing agent
atomatically
N2O should be reducing agent