The easiest way to approximate ph level is the ph paper because there are no exprimentation required and it is very handy. so it is the best way to approximate the ph level of a lake, especially when you are outdoors, and it is just an initial reading of the ph. so ph paper will do.
Answer:
c. 6.
Explanation:
Looking at the description given in the question, the elements involved must belong to the p- block of the periodic table and must be in period 5. They also must possess valence electrons in the 5p- orbital.
Now if we look at the p- block of period 5, the following elements satisfy these requirements; Sr, In, Sn, Sb, Te and I.
Hence there are six of such elements.
<span>Avogadro's number
represents the number of units in one mole of any substance. This has the value
of 6.022 x 10^23 units / mole. This number can be used to convert the number of
atoms or molecules into number of moles. We calculate as follows:
</span>1.40x10^23 molecules of N2 ( 1 mol / 6.022 x 10^23 molecules ) ( 28.02 g / mol ) = 6.51 g N2
Answer:
4. The combined volume of the Ar atoms is too large to be negligible compared with the total volume of the container.
Explanation:
Deviations from ideality are due to intermolecular forces and to the nonzero volume of the molecules themselves. At infinite volume, the volume of the molecules themselves is negligible compared with the infinite volume the gas occupies.
However, the volume occupied by the gas molecules must be taken into account. Each <u>molecule does occupy a finite, although small, intrinsic volume.</u>
The non-zero volume of the molecules implies that instead of moving in a given volume V they are limited to doing so in a smaller volume. Thus, the molecules will be closer to each other and repulsive forces will dominate, resulting in greater pressure than the one calculated with the ideal gas law, that means, without considering the volume occupied by the molecules.
