Answer:
The given metal is beryllium.
Explanation:
Given data:
Mass of metal = 74 g
Volume of metal = 40 cm³
Which metal is this = ?
Solution:
First of all we will calculate the density.
it is mass divided by volume.
d = m/v
d = 74 g/40 cm³
d = 1.85 g/cm³
In literature it is given that the density of beryllium is 1.85 g/cm³. Thus given metal is beryllium.
44.99g H2O x (1 mol H2O / 18.02g H2O) x (6.022x10^23 molecules H2O / 1 mol H2O) = 1.503x10^24 molecules H2O
Considering ideal gas behavior, the volume of 1 mol of gas at STP is 22.4 L; then the volume occupied by 1.9 moles is 1.9mol*22.4L/mol = 42. 6 L.
Answer: 43 L
Answer:

Explanation:
Hello.
In this case, taking into account that HCl has one molecule of hydrogen per mole of compound which weights 36.45 g/mol, we compute the number of molecules of hydrogen in hydrochloric acid by considering the given mass and the Avogadro's number:

Now, from the 180 g of water, we see two hydrogen molecules per molecule of water, thus, by also using the Avogadro's number we compute the molecules of hydrogen in water:

Thus, the total number of molecules turns out:

Regards.