3.

Chemistry

2 answers:

lorasvet [3.4K]3 years ago

7 0

Hey there!

CaCO₃ + HCl → CaCl₂ + CO₂ + H₂O

We have to balance Ca, C, O, Cl, and H.

Let's balance H.

One on the left, two on the right. Add a coefficient of 2 in front of HCl.

CaCO₃ + 2HCl → CaCl₂ + CO₂ + H₂O

Balance Ca.

One on the left, one on the right. Already balanced.

Balance C.

One on the left, one on the right. Already balanced.

Balance O.

Three on the left, three on the right. Already balanced.

Balance Cl.

Two on the left, two on the right. Already balanced.

Our final balanced equation:

CaCO₃ + 2HCl → CaCl₂ + CO₂ + H₂O

The answer is C. 1; 2; 1; 1; 1.

Hope this helps!

Harlamova29_29 [7]3 years ago

3 0

Answer:

C.)

Explanation:

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C. Another radioisotope of americium exists which has an atomic mass of 242.

ollegr [7]

Answer:

1 g

Explanation:

The half-life of Am-242 (16 h) is the time it takes for half of it to disappear.

We can make a table of the mass left after each half-life.

$\begin{array}{cccc}\textbf{No. of} & & \textbf{Percent} & \textbf{Mass}\\\textbf{Half-lives} & \textbf{Time/h} & \textbf{Remaining} & \textbf{Remaining/g}\\0& 0 & 100 & 8\\1 & 16 &50 & 4\\2 & 32 & 25 & 2\\3 & 48 & 12.5 & 1\\4 & 64 & 6.25 & 0.5\\\end{array}$

The mass remaining after 48 h is 1 g.

7 0

3 years ago

The molar mass of an unknown gas was measured by an effusion experiment. It was found that it took 60 s for the gas to effuse, w

Marizza181 [45]

Answer:

The molar mass of the gas is 44 g/mol

Explanation:

It is possible to solve this problem using Graham's law that says: Rates of effusion are inversely dependent on the square of the mass of each gas. That is:

$\frac{r_1}{r_2} =\frac{\sqrt{M_2} }{\sqrt{M_1} }$