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3 years ago

What phase of Moon can be ONLY seen at night?

Chemistry

2 answers:

AveGali [126]3 years ago

7 0

The phase is Waning Crescent phase.

eduard3 years ago

6 0

I think new moon but not 100% sure

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Which of these events would occur last in a food chain?

PSYCHO15rus [73]

D. An animal decaying after it dies seem to be the right answer hopefully.

4 0

2 years ago

When the equation Sn + HNO₃ → SnO₂ + NO₂ + H₂O is balanced in acidic solution, what is the smallest whole-number coefficient for

balu736 [363]

Answer:

Explanation:

Hello,

In this case, for the given reaction we first assign the oxidation state for each species:

$Sn^0 + H^+N^{5+}O^{-2}_3 \rightarrow Sn^{4+}O_2 + N^{4+}O^{2-}_2 + H^+_2O^-$

Whereas the half reactions are:

$Sn^0+2H_2O \rightarrow Sn^{4+}O_2 +4H^++4e^-\\\\H^++H^+N^{5+}O^{-2}_3 +1e^-\rightarrow N^{4+}O^{2-}_2+H_2O$

Next, we exchange the transferred electrons:

$1\times(Sn^0+2H_2O \rightarrow Sn^{4+}O_2 +4H^++4e^-)\\\\4\times (H^++H^+N^{5+}O^{-2}_3 +1e^-\rightarrow N^{4+}O^{2-}_2+H_2O)\\\\\\Sn^0+2H_2O \rightarrow Sn^{4+}O_2 +4H^++4e^-\\\\4H^++4H^+N^{5+}O^{-2}_3 +4e^-\rightarrow 4N^{4+}O^{2-}_2+4H_2O$

Afterwards, we add them to obtain:

$Sn^0+2H_2O+4H^++4H^+N^{5+}O^{-2}_3 \rightarrow Sn^{4+}O_2 +4H^++4N^{4+}O^{2-}_2+4H_2O$

By adding and subtracting common terms we obtain:

$Sn^0+4H^+N^{5+}O^{-2}_3 \rightarrow Sn^{4+}O_2 +4N^{4+}O^{2-}_2+2H_2O$

Finally, by removing the oxidation states we have:

$Sn + 4HNO_3 \rightarrow SnO_2 + 4NO_2 + 2H_2O$

Therefore, the smallest whole-number coefficient for Sn is 1.

Regards.

6 0

3 years ago

A helium-filled weather balloon has a volume of 512 L at 18.9°C and 756 mmHg. It is released and rises to an altitude of 2.14 km

vazorg [7]

633.97 L

Explanation:

Well use the combined gas law;

P₁V₁T₁ = P₂V₂T₂

We need to change the temperatures into Kelvin;

18.9°C= 292.05 K

5.9°C = 279.05 K

756 * 512 * 292.05 = 639 * V₂ * 279.05

113,044,377.6 = 178,312.95 V₂

V₂ = 113,044,377.6 / 178,312.95

V₂ = 633.97 L

3 0

2 years ago

Read 2 more answers

In the reaction Mg(s) + 2HCl(aq) → H2(g) + MgCl2(aq), how many moles of hydrogen gas will be produced from 250.0 milliliters of

satela [25.4K]

Mg + 2HCl = H₂ + MgCl₂

n(HCl)=c(HCl)v(HCl)

n(H₂)=n(HCl)/2=c(HCl)v(HCl)/2

n(H₂)=3.0mol/L*0.2500L/2=0.375 mol≈0.38 mol

5 0

3 years ago

Read 2 more answers

What is the mass of 6.02 x 1022 atoms of Xenon? HELP!!!!!

il63 [147K]

So 6.02*10^22 is avogadro constant, which is the amount of atoms in one mole. If you look Xenon up in the periodic table you will find it's mass given <span>131,293, which is grams per 1 mole.

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8 0

3 years ago