Answer:
<h3>Sand cannot mixed on water not float on water .</h3>
<h3>When we mix sand and water , No reaction take place . The sand simply settles down at the bottom of the water container . This is why sand is heavier than water and therefore cannot float in water .</h3>
<h2>Hope this helps you ✌️</h2>
Answer:

for the balanced equation

Answer:
4.90 moles of
will produce (9.8) moles of
,
(4.90) moles of
and
(39.2) moles of 
Explanation:
From the question we are told that
The number of moles of is 
The formation reaction of
is
From the reaction we see that
1 mole of
is formed by 2 moles of
1 mole of
and 4 
This implies that
4.90 moles of
will produce (2 * 4.90) moles of
,
(1 * 4.90) moles of
and
(8 * 4.90) moles of 
So
4.90 moles of
will produce (9.8) moles of
,
(4.90) moles of
and
(39.2) moles of 