INPUT ARTICLE: Article: If possible, meet where you won't be recognized. You don't want your parents, your relatives, community leaders, or your parents' friends to see you while you're out with your boyfriend. Meet when your parents think you're somewhere else, you could pretend to have a club meeting, or to be hanging out with a friend. You might even sneak out of the house at night.  If you live in a city, you could meet almost anywhere: a big city park, a free museum, a scenic hill, or a little cafe in your favorite neighborhood. The same goes for the suburbs, although it might be harder to get around if you and your boyfriend don't have your own cars. If you live in a rural area, you might need to meet up outdoors. Don't hang out with your boyfriend in the park across the street from your house, or the local supermarket, or anywhere that your parents or their friends might run into you. When you go out with your boyfriend, your parents will probably want to know where you are. It may be best to bring a friend or two with you when you go out. That way, when they call you, you can just say "Oh, I'm with Amy," and then put Amy on the phone with them to verify that indeed, you are with her and not your boyfriend! This is a classic move, but you'll need to be very careful about your story to pull off. The basic idea: if you want to meet up with your boyfriend after hours or even stay over at his house, tell your parents that you are sleeping over at a friend's house. If your parents insist on meeting your friends, then you should use a good friend (who your parents have met) to corroborate your story.  Tell your friend about your plan. If possible if you are completely certain that you can trust your friend's parents have your friend's parents agree to pretend that you're sleeping over. It helps if you name a friend whose house you've slept over at many times before. If your parents are suspicious, they might call your friend's parents to check out your story. Consider whether this is likely to happen. If so, then you may not want to risk it. Understand the risks: if you bring your boyfriend into your parents' space, then you are giving them a huge opportunity to find out about him. Wait for a time when they aren't home, a whole weekend is even better.  If you sneak your boyfriend into your house while your parents are home, make sure that he has a secret way to enter and escape. Try to bring him in once your parents are asleep, and be extremely quiet so that they don't suspect anything. Keep the noise level down so you can listen for your parents voices or footsteps in case they're walking toward your room. Be prepared to hide him under the bed or in a closet at a moment's notice, or have him leave through the window if possible! Don't leave any evidence that your boyfriend was there. Your parents will get suspicious if they see a men's comb or a men's jacket. If he gives you a gift (a note, a photo, a bouquet of flowers) don't leave it out in the open!

SUMMARY: Be careful about when and where you meet. Consider going out in groups. Say you're sleeping over at a friend's house. Be very careful about inviting your boyfriend over to your house.

INPUT ARTICLE: Article: The formula used for calculating vapor pressure given a change in the vapor pressure over time is known as the Clausius-Clapeyron equation (named for physicists Rudolf Clausius and Benoît Paul Émile Clapeyron). This is the formula you'll use to solve the most common sorts of vapor pressure problems you'll find in physics and chemistry classes. The formula looks like this: ln(P1/P2) = (ΔHvap/R)((1/T2) - (1/T1)). In this formula, the variables refer to:   ΔHvap: The enthalpy of vaporization of the liquid. This can usually be found in a table at the back of chemistry textbooks.  R: The real gas constant, or 8.314 J/(K × Mol).  T1: The temperature at which the vapor pressure is known (or the starting temperature.)  T2: The temperature at which the vapor pressure is to be found (or the final temperature.)  P1 and P2: The vapor pressures at the temperatures T1 and T2, respectively. The Clausius-Clapeyron equation looks tricky because it has so many different variables, but it's actually not very difficult when you have the right information. The most basic vapor pressure problems will give you two temperature values and a pressure value or two pressure values and a temperature value — once you have these, solving is a piece of cake.  For example, let's say that we're told that we have a container full of liquid at 295 K whose vapor pressure is 1 atmosphere (atm). Our question is: What is the vapor pressure at 393 K? We have two temperature values and a pressure, so we can solve for the other pressure value with the Clausius-Clapeyron equation. Plugging in our variables, we get ln(1/P2) = (ΔHvap/R)((1/393) - (1/295)). Note that, for Clausius-Clapeyron equations, you must always use Kelvin temperature values. You can use any pressure values as long as they are the same for both P1 and P2. The Clausius-Clapeyron equation contains two constants: R and ΔHvap. R is always equal to 8.314 J/(K × Mol). ΔHvap (the enthalpy of vaporization), however, depends on the substance whose vapor pressure you are examining. As noted above, you can usually find the ΔHvap values for a huge variety of substances in the back of chemistry or physics textbooks, or else online (like, for instance, here.)  In our example, let's say that our liquid is pure liquid water. If we look in a table of ΔHvap values, we can find that the ΔHvap is roughly 40.65 kJ/mol. Since our H value uses joules, rather than kilojoules, we can convert this to 40,650 J/mol.  Plugging our constants in to our equation, we get ln(1/P2) = (40,650/8.314)((1/393) - (1/295)). Once you have all of your variables in the equation plugged in except for the one you are solving for, proceed to solve the equation according to the rules of ordinary algebra.  The only difficult part of solving our equation (ln(1/P2) = (40,650/8.314)((1/393) - (1/295))) is dealing with the natural log (ln). To cancel out a natural log, simply use both sides of the equation as the exponent for the mathematical constant e. In other words, ln(x) = 2 → eln(x) = e2 → x = e2.  Now, let's solve our equation: ln(1/P2) = (40,650/8.314)((1/393) - (1/295)) ln(1/P2) = (4,889.34)(-0.00084) (1/P2) = e(-4.107)  1/P2 = 0.0165 P2 = 0.0165-1 = 60.76 atm. This makes sense — in a sealed container, increasing the temperature by almost 100 degrees (to almost 20 degrees over the boiling point of water) will create lots of vapor, increasing the pressure greatly

SUMMARY:
Write the Clausius-Clapeyron equation. Plug in the variables you know. Plug in your constants. Solve the equation.