chemistry

How do you know the state of an element or compound when writing chemical equations?


Unless otherwise known, assume the state of the element at room temp. Here is the real problem. For aqueous compounds, ie, compounds dissolved in water, you have to have that given. There is a big difference between NaCl (s) and NaCl (aq).Most common acids are in water, for instance HCl, H2SO4, HNO3. These are written HCl (aq). For products, often the product is not soluble in water, and it precipates...you will learn this later, anyway, here is an example:

NaCl (aq, saturated) + HCl (aq, conc)>>NaCl (s) + HCl (aq) + NaCl (aq, sat)

notice how some of the salt changes to a solid? Neat trick, your teacher may demonstrate this to your class some day, I hope so.


I will expand a little on the previous answer you have been given by Anonymous. His explanation is ok for compounds. Your question also covered elements and his answer is to take the state at room temperature. But what is that state? I will expand on that. If you have a periodic table handy, take a look at those elements listed. Almost all elements are solid at room temperature. The solid elements on my table are listed in black. There are a few exeptions. There are two liquids, shown in blue on my table, Br and Hg. There are 11 gases, shown in red on my table. H2, F2, Cl2, N2, O2, He, Ne, Ar, Kr, Xe. and Rn. So if you know the six inert gases and the other five gases plus the two liquids, everything else is solid. Some may argue that Fr, Cs, and Ga (shown on my table the same color as Br and Hg as liquids) are liquids but Ga has a melting point of 29.8, Fr has a m.p. of 27, and Cs has a m.p. of 28.4. A room temperature of 25 degrees C is 77 degrees F and these are higher than that. (The lowest of 27 corresponds to 80.6 degrees F.) I don't call that a compfortable room temperature and I don't consider them liquids. In addition to that, I think only a few atoms of Fr have been produced so that really isn't an issue. I hope this is useful.

  1. 👍
  2. 👎
  3. 👁

Respond to this Question

First Name

Your Response

Similar Questions

  1. chemistry

    Identify the neutral element represented by this excited-state electron configuration, then write the ground-state electron configuration for that element. Excited State: 1s2 2s2 2p2 3s1 Element Symbol: ? Ground State: ?

  2. Chemistry

    Element x has the highest first electron affinity in its period, the ground state electron configuration of its common is: [Kr] 5s2 4d10 5p6 Element Y is the second largest element in its period; its valence electron are in

  3. Science--Help.

    Which of the following is NOT one of the eight most common elements in Earth’s continental crust? carbon silicon oxygen aluminum The most abundant element in Earth’s continental crust (by weight) is _____. 2. oxygen silicon

  4. Science

    4.)When two or more atoms of the same of the same element are in a chemical bond, the substance is called a(n)________ A.)Compound B.)Molecule C.)Nucleus D.)Particle*** Am I'm correct? BUT My mom disagree's and says C?, isn't she

  1. science

    An unknown element X forms a compound with bromine: XBr. Predict the chemical formula of the compound that element X makes with oxygen. Justify your answer.

  2. absloute values math

    An equation that describes the maximum and minimum temperatures at which a chemical compound is in a liquid state is given by the absolute value equation |T - 50 |= 50, where T is the temperature in degrees Celsius. Calculate the

  3. Adv Chem 12th grade

    4. Given the chemical formulas of the following compounds, name each compound and state the rules you used to determine each name. • RbF • CuO • (NH4)2C2O4 (Note: C2O4– is called oxalate.)

  4. Science

    Review the information. In Compound A, Element W has an electronegativity of 2.8, and Element X has an electronegativity of 2.5. In Compound B, Element Y has an electronegativity of 2.0, and Element Z has an electronegativity of

  1. A.P Chemistry

    Three volatile compounds X,Y, and Z each contain elements Q. The precent by weight of element Q in each compound was determined. Some of the data obtained are given below Percent by weight Molecular Compound of Element Q Weight X

  2. Chemistry

    An element X with the electronic configuration: 1s2, 2s2, 2p6, 3s2, 3p3. Derive the chemical formula of the compound formed.

  3. science

    IDK these help pls 1. Which of the following is a compound? A. O2 B. NH3 C. H2O+NaCl D. N2 2. What is the difference between compounds and mixtures? A. Compounds contain only one element; mixtures contain two or more elements. B.

  4. Physical science

    What happens when an atom gives up loosely held valence electrons to another atom? A. The two atoms form a mixture. B. A chemical bond forms between the two atoms. C. A chemical compound splits into separate elements. D. The two

You can view more similar questions or ask a new question.