Question

8 multiple choice 1 point which of these is a compound? shaving cream iron nacl milk 9 formula 1 point a gas balloon has a volume of 4.4 liters when the temperature is 18.9°c and the pressure is 732.7 mm of mercury. what will its volume be, in l, at 28.3°c and 716.5 mm of mercury pressure? express your answer with 1 decimal place. answer 10 numeric 1 point how many significant figures are in 0.051 l? answer

Explanation:

Question 8

A compound is a substance formed when two or more elements are chemically bonded together. Shaving cream and milk are mixtures. Iron (\(Fe\)) is an element. \(NaCl\) (sodium chloride) is formed by the chemical combination of sodium (\(Na\)) and chlorine (\(Cl\)) elements.

Step1: Convert temperatures to Kelvin

The formula to convert Celsius to Kelvin is \(T(K)=T(^{\circ}C)+ 273.15\).
For the initial temperature \(T_1 = 18.9+273.15=292.05\ K\)
For the final temperature \(T_2=28.3 + 273.15=301.45\ K\)

Step2: Use the combined gas law \(\frac{P_1V_1}{T_1}=\frac{P_2V_2}{T_2}\)

We are given \(P_1 = 732.7\ mmHg\), \(V_1 = 4.4\ L\), \(T_1=292.05\ K\), \(P_2 = 716.5\ mmHg\), \(T_2 = 301.45\ K\)
We need to solve for \(V_2\). Rearranging the combined - gas law formula gives \(V_2=\frac{P_1V_1T_2}{P_2T_1}\)
Substitute the values:
\(V_2=\frac{732.7\times4.4\times301.45}{716.5\times292.05}\)
First, calculate the numerator: \(732.7\times4.4\times301.45=(732.7\times4.4)\times301.45 = 3223.88\times301.45\approx971738.826\)
Then, calculate the denominator: \(716.5\times292.05=(700 + 16.5)\times292.05=700\times292.05+16.5\times292.05=204435+4818.825 = 209253.825\)
\(V_2=\frac{971738.826}{209253.825}\approx4.6\ L\)

Leading zeros (zeros before non - zero digits) are not significant. In the number \(0.051\), the non - zero digits are \(5\) and \(1\).

Answer:

NaCl

Question 9