Answer:
Los pulmones y el aparato respiratorio nos permiten respirar. Permiten la entrada de oxígeno en nuestros cuerpos (inspiración o inhalación) y expulsan el dióxido de carbono (expiración o exhalación). Este intercambio de oxígeno y dióxido de carbono recibe el nombre de "respiración"
La función del aparato respiratorio es mover dos gases: <em>el oxígeno y el dióxido de carbono</em>
Explanation:
Answer: Polythene
Polythene is a synthetic polymer classified as plastics.
Explanation:
Polythene is formed artificially from several repeating units of ethene molecules (monomers) in a reaction known as polymerization.
The polyethene can be represented as [CH2-CH2]n, where n is thousands to ten thousands unit of ethene.
It is used to make
- plastic bags,
- cable insulators
- plastic crates etc
Thus, polythene is a synthetic polymer of ethene, and classified as plastics.
<span>The "p" in pH and pOH stands for "negative logarithm of" and is used to make it easier to work with extremely large or small values. pH and pOH are only meaningful when applied to aqueous (water-based) solutions. </span>
Answer:
Concentration of sodium carbonate in the solution before the addition of HCl is 0.004881 mol/L.
Explanation:

Molarity of HCl solution = 0.1174 M
Volume of HCl solution = 83.15 mL = 0.08315 L
Moles of HCl = n



According to reaction , 2 moles of HCl reacts with 1 mole of sodium carbonate.
Then 0.009762 mol of HCl will recat with:

Moles of Sodium carbonate = 0.004881 mol
Volume of the sodium carbonate containing solution taken = 1L
Concentration of sodium carbonate in the solution before the addition of HCl:
![[Na_2CO_3]=\frac{0.004881 mol}{1 L}=0.004881 mol/L](https://tex.z-dn.net/?f=%5BNa_2CO_3%5D%3D%5Cfrac%7B0.004881%20mol%7D%7B1%20L%7D%3D0.004881%20mol%2FL)