1) Dalton stated that atom is matter that can not be divided, but it is proved that the atom can be divided into subatomic particles (electrons, protons and neutrons).
2) He stated that atoms of one element can not be changed into atoms of other elements, but now that is possible by nuclear reactions.
Today we still use his postulate: Atoms combine in the ratio of small whole numbers to form stable compounds, for example H₂O.
compound name compound formula elements present
water H2O hydrogen (H) and oxygen (O)
ammonia NH3 nitrogen (N) and hydrogen (H)
carbon monoxide CO carbon (C) and oxygen (O)
carbon dioxide CO2 carbon (C) and oxygen (O)
Answer:
determine the absolute age of rocks.
Answer:
1. Synthesis
2. Decomposition
3. Single replacement
4. Synthesis
5. Decomposition
6. Synthesis
Explanation:
Kind of a hard picture to look at but let me define each chemical reaction:
Synthesis:
a + b ---> ab In synthesis elements/compounds come together to form new compounds
Decomposition:
ab ---> a + b In decomposition a compound breaks down to form 2 elements/compounds
Single replacement:
a + bc ---> b + ac In a single replacement one element/compound takes the place of another element/compound.
Double replacement
ab + cd ---> ad + bc In a double replacement 2 compounds exchange different elements/compounds.
Now, let's go through the assignment
1. P + O2 --> P4O10 This is a synthesis reaction because the two elements (P and O) came together to form one compound.
2. HgO ---> Hg + O2 This is a decomposition reaction because HgO broke into separate elements Hg and O.
3. Cl2 + NaBr ---> NaCl + Br2 This is a single replacement reaction because chlorine (Cl) replaced the spot of bromine (Br) to bond with sodium (Na).
4. Mg + O2 ---> MgO This is a synthesis reaction because two elements (Mg and O) came together to form one compound.
5. Al2O3 ---> Al + O2 This is a decomposition reactions because Al2O3 broke into separate elements Al and O.
6. H2 + N2 ---> NH3 This is a synthesis reaction because two elements (H and N) came together to form one compound.
<em>I hope this helps!!</em>
<em>- Kay :)</em>
Answer:
49.95 g of HCl
Explanation:
Let's formulate the chemical equation involved in the process:
Ca(OH)2 + 2 HCl → CaCl2 + 2 H2O
This means that we need 1 mole of Calcium hydroxide to neutralize 2 moles of hydrochloric acid. From this, we calculate the quantity of HCl moles that would be neutralized by 0.685 moles of Ca(OH)2
1 mole Ca(OH)2 ---- 2 moles HCl
0.685 moles Ca(OH)2 ---- x = 1.37 moles HCl
Now that we know the quantity of HCl moles that would react, let's calculate the quantity of grams this moles represent:
1 mole of HCl ---- 36.46094 g
1.37 moles ------ x = 49.95 g of HCl