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First Five for January 26 and 27

STOICHIOMETRY!

How many grams of oxygen are need to burn 360 grams of glucose? 

C6H12O6  +  6 O2   →  6 CO2 + 6 H2O

Posted in Chemistry, First Five

First Five for January 24 and 25

Balance each of the following equations:

 

1.         ____ C3H8 + ____O2  →     ____CO2 + ____ H2O

 

2.        ____ P4 + ____ O2  →    ____ P2O5

 

3.        ____ AlBr3 + ____ Cl2   →     ____ AlCl3 + ____ Br2

 

4.        ____ H2 + ____ N2  →       ____ NH3

Posted in Chemistry, First Five

First Five for January 23

Match the descriptors at left with the appropriate particle(s) on the right.

Descriptors:

  • Mass# = 1

  • Mass# = 0

  • Positive

  • Negative

  • Neutral

  • found in the nucleus

  • found outside the nucleus

  1. Electron

  2. Proton

  3. Neutron

Posted in Chemistry, First Five

First Five for January 19 and 20

Identify each of the following isotopes by the name – mass # format:

  1.      8 protons, 9 neutrons, 8 electrons

  2.      80 protons, 120 neutrons, 80 electrons

  3.      38 protons, 46 neutrons, 38 electrons

Identify the element class to which each atom above belongs.

Posted in Chemistry, First Five

First Five for January 17 & 18

Complete the following conversion problems:

1. How many moles of methane are in a 96 gram sample of methane, CH4?

2. What is the mass, in grams,  of the sample 0.25 moles of methane?

Posted in Chemistry, First Five

First Five for January 12 and 13

Identify the missing particle in the following equation. What type of decay is taking place?

_{92}^{235}\textrm{U} \to\; _{90}^{231}\textrm{Th}\; +

Identify the particle formed when an atom of aluminum-28 undergoes beta decay.

Posted in Chemistry, First Five

First Five for January 10 and 11

Draw Lewis electron dot structures for the following diatomic molecules:

Hydrogen (H2), nitrogen (N2), Oxygen (O2), Fluorine (F2)

 

Posted in Chemistry, First Five

First Five for January 9

Match the vocabulary term on top with the definition below.

Theory, Hypothesis, Experiment, Observations

_____________________Information obtained through the senses

_____________________A well tested explanation for a broad set of observations

_____________________A proposed explanation for an observation

_____________________A repeatable procedure that is used to test a hypothesis

Posted in Chemistry, First Five

First Five for December 8 and 9

Draw Lewis electron dot structures for the following diatomic molecules:

  • H2

  • O2

  • Cl2

  • N2

Posted in Chemistry, First Five

First Five for December 6 and 7

Write the electron configuration notation and the Lewis dot notation for an atom of sulfur (S), atomic number 16. Name two other nonmetals that would have the same number of valence electrons.

Write the electron configuration notation for a sulfide ion.

Posted in Chemistry, First Five