supply either the missing formula or name, & 2nd name for acids & covalent (rchem may skip 2nd name)
hydrogen carbonate
Magnesium sulfide
Sodium carbonate
Hl
CrO
KOH
Carbon IV oxide
H2SO3
Hydrogen chloride
NO
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Give the formulas; for acids and covalent compounds, give a 2nd name(rchem may skip second name
potassium nitride
nickel III nitride
nitrite
hydrogen chlorate
phosphorus trioxide
hydrogen nitrite
nitrogen VI oxide
hydrogen chloride
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find % sugar in gum from data. 3.00g before, 1.20g after chewing.
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salt water lab also on test! ch7 saltwater d&%
mass of dish 38.0g
mass of dish and 15mL of saltwater 59.0g
mass of dish and salt after oven 42.5g
mass of salt
mass of water
density of salt water
% salt in salt water
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A hydrate, barium sulfide triihydrate, is heated, and the following data is obtained.
Mass of empty dish 34.06g
Mass of dish and hydrate 37.08g.
Mass of dish and chemical after heating 36.85g.
Mass in g of the hydrate
Mass in g of the anhydrous salt
Mass in g of the water.
% water in the hydrate from the experiment WORK:
% water in the hydrate from the formula WORK:
% error WORK:
moles of water in the hydrate (from data) work:
moles of anhydrous salt work:
hchem only: is the answer what is expected?
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formula mass of CH4
Common name and important uses (in our lab and in your home) of CH4
Formula mass of Sodium sulfate in amu
% S in Sodium sulfate WORK:
% O in Sodium sulfateWORK:
% Na in Sodium sulfate WORK:
How many atoms in 20g of Lithium? Show work
How many moles are 88g of carbon dioxide? How many molecules? WORK:
What is the mass in grams of 0.55 moles of carbon monoxide? WORK:
mass of 1 mole of sulfur VI oxide in g
moles of water present in 162g of water WORK:
mass of 0.61 mole of water in g WORK:
If you shared one mole of water, How many molecules could be given to each person in the world (population link)?
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Indicate which formulas are not empirical by finding the empirical formula.
salt, glucose (C6H12O6), methane, C2H6, Al2(SO4)3
A sample of a compound decomposes into 92.3gC and 15.4gH ; it has a molar mass of 42g.
How many moles of H is 15.4g? WORK:
How many moles of carbon is 92.3g? WORK:
What is the mole ratio of H to C? WORK:
What is the empirical formula?
rchem may stop here_______________________
What is the molecular to empirical formula ratio? WORK:
What is the molecular formula?
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p 253 (e242) #36-39 & p249 empirical and molecular formula problems; see sample problems in the text
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a chemist does not know the formula of a hydrate of sodium sulfate, so he heats the hydrate, obtaining the following data;
empty dish 32.50g
dish and hydrate 35.63g
dish and anhydrous salt 33.83
based on this information, what is the formula of the hydrate? Show work to justify your answer!
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_________________________________________ mg part below, skip for dec 2021
Why does magnesium gain mass when it burns, but wood loses mass when it burns? What is rust? Would an object appear to gain or lose mass as it rusts? Why?
Some magnesium metal is put into a crucible and heated, forming magnesium oxide. The following data is collected.
dish 13.45g
dish & Mg 15.88g
dish and MgO 19.08g
What is the mass of O? Find the exp% O.
rchem may skip the bolded questions 1-3
1Moles of oxygen (from data)WORK:
2Moles of metal (from data)WORK:
3Is this the mole ratio expected? Explain