{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

HW 1 Atomic Theory - roberts(eer474 Homework 1 Atomic...

Info icon This preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
roberts (eer474) – Homework 1: Atomic Theory – Shear – (52375) 1 This print-out should have 21 questions. Multiple-choice questions may continue on the next column or page – find all choices before answering. This homework includes some questions that test basic chemistry knowledge. Some may need you to look things up like atomic masses, fundamental constants, and unit con- versions. Here are some that you may need: c = 3 . 00 × 10 8 m/s h = 6 . 626 × 10 - 34 J · s m e = 9 . 11 × 10 - 31 kg N A = 6 . 022 × 10 23 mol - 1 Δ E = R parenleftbigg 1 n 2 1 - 1 n 2 2 parenrightbigg where R = - 2 . 178 × 10 - 18 J ψ n ( x ) = parenleftbigg 2 L parenrightbigg 1 2 sin parenleftBig nπx L parenrightBig E n = n 2 h 2 8 mL 2 n = 1 , 2 , 3 , · · · 001 10.0 points Which of water, iron, ammonia, chromium, radon, and silicon are chemical compounds as opposed to elements? 1. only water 2. iron and silicon 3. radon and ammonia 4. chromium and water 5. water and ammonia correct Explanation: Water (H 2 O) and ammonia (NH 3 ) are com- posed of more than one element and are com- pounds. 002 10.0 points Identify the symbols for the elements phos- phorus, potassium, silver, chlorine, and sul- fur, in that order. 1. Ph, K, Ag, S, Cl 2. K, Ag, Po, Cl, S 3. P, K, Ag, Cl, S correct 4. P, Po, Ag, Cl, S 5. Ph, Po, Ag, Al, S Explanation: The symbol for phosphorus is P, for potas- sium K, for silver Ag, for chlorine Cl, and for sulfur S. 003 10.0 points Convert 45 micrograms to grams. 1. 4 . 5 × 10 10 g 2. 4 . 5 × 10 7 g 3. 4 . 5 × 10 - 11 g 4. 0.045 g 5. 45000 g 6. 4 . 5 × 10 - 5 g correct 7. 4 . 5 × 10 - 8 g 8. 4 . 5 × 10 13 g Explanation: 45 micrograms · parenleftbigg 1 g 10 6 μ g parenrightbigg = 4 . 5 × 10 - 5 g 004 10.0 points Find the molar mass for Ba(OH) 2 . 1. 172.34 g/mol 2. 170.32 g/mol 3. 153.31 g/mol 4. 171.35 g/mol correct
Image of page 1

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
roberts (eer474) – Homework 1: Atomic Theory – Shear – (52375) 2 5. 155.33 g/mol Explanation: molar mass of Ba(OH) 2 = ? 1 mol Ba × 137.33 g Ba mol Ba = 137.33 g 2 O mol × 16.00 g O mol O = 32.00 g 2 mol H × 1.01 g O mol H = 2.02 g Molar mass = 171.35 g /mol 005 10.0 points Balance the equation ? CS 2 + ? O 2 ? CO 2 + ? SO 2 What are the coefficients? 1. 2, 1, 2, 1 2. 1, 2, 1, 2 3. 2, 1, 1, 2 4. 1, 2, 3, 1 5. 2, 2, 1, 1 6. 1, 2, 1, 1 7. 1, 3, 1, 2 correct Explanation: C is balanced. O is not balanced, but because it is in both products, we will leave that until the end. Let’s start with S. There are 2 S on the left and 1 S on the right so we will add one more S on the right.
Image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern