Answer:
9
Explanation:
mass number = protons + neutrons
= 4 + 5 = 9
DE = dH - PdV
<span>2 H2O(g) → 2 H2(g) + O2(g) </span>
<span>You can see that there are 2 moles of gas in the reactants and 3 moles of gas in the products. </span>
<span>1 moles of ideal gas occupies the same volume as 1 mole of any other ideal gas under the same conditions of temp and pressure. </span>
<span>Since it is done under constant temp and pressure that means the volume change will be equal to the volume of 1 mole of gas </span>
<span>2 moles reacts to form 3 moles </span>
<span>The gas equation is </span>
<span>PV = nRT </span>
<span>P = pressure </span>
<span>V = volume (unknown) </span>
<span>n = moles (1) </span>
<span>R = gas constant = 8.314 J K^-1 mol^-1 </span>
<span>- the gas constant is different for different units of temp and pressure (see wikki link) in this case temp and pressure are constant, and we want to put the result in an equation that has Joules in it, so we select 8.314 JK^-1mol^-1) </span>
<span>T = temp in Kelvin (kelvin = deg C + 273.15 </span>
<span>So T = 403.15 K </span>
<span>Now, you can see that PV is on one side of the equation, and we are looking to put PdV in our dE equation. So we can say </span>
<span>dE = dH -dnRT (because PV = nRT) </span>
<span>Also, since the gas constant is in the unit of Joules, we need to convert dH to Joules </span>
<span>dH = 483.6 kJ/mol = 483600 Joules/mol </span>
<span>dE = 483600 J/mol - (1.0 mol x 8.314 J mol^-1K-1 x 403.15 K) </span>
<span>dE = 483600 J/mol - 3351.77 J </span>
<span>dE = 480248.23 J/mol </span>
<span>dE = 480.2 kJ/mol </span>
The enthalpy change for melting ice is called the entlaphy of fusion. Its value is 6.02 kj/mol. This means for every mole of ice we melt we must apply 6.02 kj of heat. We can calculate the heat needed with the following equation:
Q = N x ΔH
where:
Q = heat
N = moles
ΔH = enthalpy
In this problem we would like to calculate the heat needed to melt 35 grams of ice at 0 °C. This problem can be broken into three steps:
1. Calculate moles of water
2. multiply by the enthalpy of fusion
3. Convert kJ to J.
Step 1 : Calculate moles of water
![[ 75g ] x (\frac{1 mol}{18.02g} ) =](https://tex.z-dn.net/?f=%5B%2075g%20%5D%20x%20%28%5Cfrac%7B1%20mol%7D%7B18.02g%7D%20%29%20%3D)
Step 2 : Multiply by enthalpy of fusion
Q = N × ΔH = <em> [ Step 1 Answer ]</em> × 6.02 =
Step 3 : Convert kJ to J
![[ Step 2 Answer ] x (\frac{1000j}{1kJ} ) =](https://tex.z-dn.net/?f=%5B%20Step%202%20Answer%20%5D%20x%20%28%5Cfrac%7B1000j%7D%7B1kJ%7D%20%29%20%3D)
Finally rounding to 2 sig figs (since 34°C has two sig figs) we get
Q Would Equal ____
Answer:
slippery, high pH, and caustic (last option)
Explanation:
when we say base we should think soap. soap is slippery. Bases give OH- ion. when OH- is combined with H+ ion it will create water which raises the pH. Since base can dissolve fats, ex: using dish liquid to cut grease on pots and pans etc.. they are caustic. Biologically they can disrupt the cell memebrane making it caustic to cell tissue.
