5. how many grams of na2co3 are there in 10.0l of a 2.0m solution?

Explanation:

Step1: Calculate moles of $Na_2CO_3$

Use the formula $n = M\times V$, where $n$ is the number of moles, $M$ is the molarity and $V$ is the volume in liters. Given $M = 2.0\ mol/L$ and $V=10.0\ L$. $n = 2.0\ mol/L\times10.0\ L=20\ mol$

Step2: Calculate molar - mass of $Na_2CO_3$

The molar - mass of $Na$ is approximately $23\ g/mol$, $C$ is approximately $12\ g/mol$ and $O$ is approximately $16\ g/mol$. $M_{Na_2CO_3}=2\times23 + 12+3\times16=46 + 12+48 = 106\ g/mol$

Step3: Calculate mass of $Na_2CO_3$

Use the formula $m=n\times M$, where $m$ is the mass, $n$ is the number of moles and $M$ is the molar - mass. $m = 20\ mol\times106\ g/mol = 2120\ g$

Answer:

2120 g