Ask question

Ask question

All categories

2 years ago

7

Why is oxygen an element ? a it is essential to life b it burn c it combines with hydrogen d it cannot be broken down into a sim

ple substance through chemical means

2 answers:

MrRa [10]2 years ago

5 0

D.) It cannot be broken down into a simple substance through chemical means...

lesya [120]2 years ago

4 0

Answer:

D, oxygen cannot be broken down into a simple substance through chemical means,

Explanation:

You might be interested in

Determine the mass of CaCO3 required to produce 40.0 mL CO2 at STP. Hint use molar volume of an ideal gas (22.4 L)

cupoosta [38]

Answer:

$m_{CaCO_3}=0.179gCaCO_3$

Explanation:

Hello,

In this case, since the undergoing chemical reaction is:

$CaCO_3(s)\rightarrow CaO(s)+CO_2(g)$

The corresponding moles of carbon dioxide occupying 40.0 mL (0.0400 L) are computed by using the ideal gas equation at 273.15 K and 1.00 atm (STP) as follows:

$PV=nRT\\\\n=\frac{PV}{RT}=\frac{1.00 atm*0.0400L}{0.082\frac{atm*L}{mol*K}*273.15 K})=1.79x10^{-3} mol CO_2$

Then, since the mole ratio between carbon dioxide and calcium carbonate is 1:1 and the molar mass of the reactant is 100 g/mol, the mass that yields such volume turns out:

$m_{CaCO_3}=1.79x10^{-3}molCO_2*\frac{1molCaCO_3}{1molCO_2} *\frac{100g CaCO_3}{1molCaCO_3}\\ \\m_{CaCO_3}=0.179gCaCO_3$

Regards.

3 0

3 years ago

Calculate the energy, in joules, required to ionize a hydrogen atom when its electron is initially in the n =2 energy level. The

qaws [65]

Answer:

$E_{ionization}=5.45\times 10^{-19}\ J$

Explanation:

$E_n=-2.18\times 10^{-18}\times \frac{1}{n^2}\ Joules$

For transitions:

$Energy\ Difference,\ \Delta E= E_f-E_i =-2.18\times 10^{-18}(\frac{1}{n_f^2}-\frac{1}{n_i^2})\ J=2.18\times 10^{-18}(\frac{1}{n_i^2} - \dfrac{1}{n_f^2})\ J$

$\Delta E=2.18\times 10^{-18}(\frac{1}{n_i^2} - \dfrac{1}{n_f^2})\ J$

So, $n_i=2$ and $n_f=\infty$ (As the hydrogen has to ionize)

Thus,

$\Delta E=2.18\times 10^{-18}(\frac{1}{2^2} - \dfrac{1}{{\infty}^2})\ J$

$\Delta E=2.18\times 10^{-18}(\frac{1}{2^2})\ J$

$E_{ionization}=5.45\times 10^{-19}\ J$

4 0

3 years ago

What are three ways heat is transfered

Gre4nikov [31]

Answer:

Conduction, Convection and Radiation

Explanation:

6 0

2 years ago

Read 2 more answers

pishuonlain [190]

Answer:

B

Explanation:

Boyle was known for rejecting Aristotle's theory basing it on the four elements (earth, air, fire, water).

4 0

3 years ago

What happens to the pressure of a gas inside a rigid container if the temperature of a gas decreases?

NikAS [45]

Answer:

If the temperature of gas is decreased the pressure will also goes to decrease.

Explanation:

The pressure and temperature have direct relation. If the temperature of gas will increase the pressure of gas will also goes to increase.

According to the Gay-Lussas's Law,

The pressure of given amount of gas is directly proportional to the absolute temperature when volume is kept constant.

Mathematical relationship:

P ∝ T

P = kT

P/T = k

and

P₁/T₁ = P₂/T₂

5 0

2 years ago