4. 90 g of zinc are placed in hydrochloric acid (HCI). How many grams of zinc chloride are
produced?

188.31g of ZnCl2

Explanation:

First, we need to write a balanced equation for the reaction between Zn and HCl. This is shown below:

Zn + 2HCl —> ZnCl2 + H2

Molar Mass of Zn = 65g/mol

Molar Mass of ZnCl2 = 65 + (2x35.5) = 65 + 71 = 136g/mol

From the equation,

65g of Zn produced 136g of ZnCl2.

Therefore, 90g of Zn will produce = (90 x 136)/65 = 188.31g of ZnCl2

number of molecules / avogadro's number * molecule molecular = mass

explanation:

we define a gram-molecular weight as the mass of one mole of any element or compound. a mole contains avogadro's number of units (molecules) –  

6.022

x

10

23

. so, dividing the number of molecules by avogadro's number gives us the number of moles. multiplying that by the molecular weight gives us the mass. from the periodic table we find the gram-molecular weight of u to be238 and of f to be19. so,  

u

f

6

will have a gram-molecular weight of 352g.

they are made of gases.

they have a spherical shape.

they make energy through fusion.