Answer: It becomes the uncombined element in the product.
Explanation:
The reaction between Zn and HCl is a single displacement reaction according to equation below
Zn + 2HCl —> ZnCl2 + H2
Zn displaces H2 from acid and in the product, hydrogen became the uncombined element.
The balanced chemical reaction is:
<span>2H2+O2-->2H2O
</span>
To determine the mass of hydrogen that is needed, we need use the initial amount of oxygen and relate it to hydrogen from the reaction given. We do as follows:
192 g O2 ( 1 mol O2 / 32 g O2) ( 2 mol H2 / 1 mol O2 ) ( 2.02 g H2 / 1 mol H2 ) = 24.24 g H2
Answer:
36
Explanation:
Since the sample was undiluted the number of colonies is the number that grew on the nutrient agar which is 36 colonies. If it was diluted for example let say 0.1 ml from a dilution in which 1 ml of the sample was added to 9 ml of water, and it grew colonies then 0.1 ml yielded 6 colonies, 1 ml of the diluted sample will yield 60 colonies and 10 ml will have 600 colonies and therefore the 1 ml undiluted sample will have 600 colonies.
Answer:
, zirconium-103.
Explanation:
In a nuclear reaction, both the mass number and atomic number will conserve.
Let 
represent the unknown particle.
The mass number of a particle is the number on the upper-left corner. The atomic number of a particle is the number on its lower-left corner under the mass number. For example, for the particle , 
is the mass number while 
while is the atomic number.
Sum of mass numbers on the left-hand side of the equation:
.
Note that there are three neutrons on the right-hand side of the equation. Sum of mass numbers on the right-hand side:
.
Mass number conserves. As a result,
.
Solve this equation for :
.
Among the five choices, the only particle with a mass number of 103 is . Make sure that atomic number also conserves.
