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3 years ago

What is the first element of the periodic table?

2 answers:

7 0

The first element of the periodic table is Hydrogen. It is the only element that can achieve being stable without a full octet (8 valence electrons).

Answer: Hydrogen

Tpy6a [65]3 years ago

3 0

Hyrdrogen.
I hope this helps;)

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Hydrogen gas can combine with oxygen gas under certain conditions to form water. Which name is a general term for water in this

antoniya [11.8K]

Product

Explanation:

Water in this reaction is called the product of the reaction.

The product is the new kind of matter formed as a result of a chemical change. They are produced from the combination of reactants.

2H₂ + O₂ → 2H₂O

Reactants Products

A chemical reaction involves the combination of chemical species to form a product. The type of reaction above is a called synthesis reaction.

learn more:

Chemical equation brainly.com/question/5247791

#learnwithBrainly

8 0

2 years ago

one reaction that produces hydrogen gas can be represented by the unbalanced chemical equation Mg(s)+HCI(aq) -> MgCI(aq)+H2(g

Sonbull [250]

<h3>Answer:</h3>

128 g HCl

<h3>General Formulas and Concepts:</h3>

<u>Pre-Algebra</u>

Order of Operations: BPEMDAS

Brackets
Parenthesis
Exponents
Multiplication
Division
Addition
Subtraction

Left to Right<u> </u>

<u>Chemistry</u>

<u>Atomic Structure</u>

Reading a Periodic Table

<u>Stoichiometry</u>

Reaction Mole Ratios
Using Dimensional Analysis

<h3>Explanation:</h3>

<u>Step 1: Define</u>

[RxN - Unbalanced] Mg (s) + HCl (aq) → MgCl (aq) + H₂ (g)

↓

[RxN - Balanced] 2Mg (s) + 2HCl (aq) → 2MgCl (aq) + H₂ (g)

[Given] 3.25 mol Mg

[Solve] x g HCl

<u>Step 2: Identify Conversions</u>

[RxN] 2 mol Mg → 2 mol HCl

[PT] Molar Mass of H - 1.01 g/mol

[PT] Molar Mass of Cl - 35.45 g/mol

Molar Mass of HCl - 1.01 + 35.45 = 36.46 g/mol

<u>Step 3: Stoich</u>

[S - DA] Set up: $\displaystyle 3.25 \ mol \ Mg(\frac{2 \ mol \ HCl}{2 \ mol \ Mg})(\frac{36.46 \ g \ HCl}{1 \ mol \ HCl})$
[S - DA] Multiply/Divide [Cancel out units]: $\displaystyle 127.61 \ g \ HCl$

<u>Step 4: Check</u>

<em>Follow sig fig rules and round. We are given 3 sig figs.</em>

127.61 g HCl ≈ 128 g HCl

3 0

2 years ago

A sealed reaction vessel initially contains 1.113×10-2 moles of water vapor and 1.490×10-2 moles of CO(g).

Molodets [167]

Answer:

Kc = $\frac{[8.326x10-3]^{1} }{[1.113x10-2]^{1}[1.490x10-2]^{1} }$

Kc = 50.2059

Explanation:

1. Balance the equation

2. Use the Kc formula

Remember that pure substances, like H2 are not included on the Kc formula

4 0

3 years ago

Complete and balance the following neutralization reaction Ca(OH)2 + H2SO4

Debora [2.8K]

Answer: Ca(OH)2 (aq) + H2SO4 (aq) ----------> CaSO4(aq) + 2H2O(l)

Explanation:

Since this is a neutralization reaction, the end product would be salt and water. In this equation Calcium will displace hydrogen from the acid because it is more reactive, resulting in the formation of CaSO4 (salt), while the displaced H2 molecule combines with OH molecules to form water.

The equation of the reaction is thus;

Ca(OH)2 (aq) + H2SO4 (aq) ----------> CaSO4(aq) + H2O(l), in other to balance it, we add ''2'' to the water molecule in the right hand side of the equation.

Balance equation is

Ca(OH)2 (aq) + H2SO4 (aq) ----------> CaSO4(aq) + 2H2O(l)

6 0

2 years ago

What is the total enthalpy change for the reaction? Is the reaction exothermic or endothermic?

Nuetrik [128]

Answer: S8(s) + 8O2(g) → 8SO2(g) ΔH = -2368 kJ a.

8 0

2 years ago