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Which of the following answers shows CH4 +2O2=CO2 +H2O as balanced?

A. CH4 + 2O2 = 2CO2 + 2H2O

B. 2CH4 + 4O2 = 2CO2 + H2O

C. 2CH4 + O2 = 2CO2 + H2O

D. CH4 + 2O2 = CO2 + 2H2O

Answer Explanation:

For the formula CH4 + 2O2 = CO2 + H2O to be balanced there must be an equal number of molecules on both the reactant and product sides. In this case, for the formula to be balanced, a coefficient of a 2 needs to be placed in front of the O2 and the H2O molecules. This would make both the reactant and product sides have one carbon, four hydrogens, and four oxygens

Therefore, the Correct Answer is D.

More Questions on TEAS 7 Science

  • Q #1: Which of the following orbitals is the last to fill?

    A. 1s

    B. 3s

    C. 4p

    D. 6s

    Answer Explanation

    Of these orbitals, the last to fill is 6s.

    Orbitals fill in the following order: 1s, 25, 2p. 35, 3p, 4s, 3d, 4p, 55, 4d, 5p. 6s, 4f, 5d, 6p. 7s, 5f, 6d, and 7p. The number is the orbital number, and the letter is the sublevel identification. Sublevels has one orbital and can hold a maximum of two electrons. Sublevel p has three orbitals and can hold a maximum of six electrons. Sublevel d has five orbitals and can hold a maximum of 10 electrons, Sublevel f has seven orbitals and can hold a maximum of 14 electrons.

  • Q #2: How many tissue layers does the uterus have?

    A. One

    B. Two

    C. Three

    D. Four

    Answer Explanation

    The uterus has three layers. The inner layer is called the endometrium. The middle layer is called the myometrium. The outer layer of the uterus is called the serosa or perimetrium.

  • Q #3: When animals eat, insulin is released from the pancreas, stimulating glucose uptake by the liver. When glucose levels drop, the pancreas reduces insulin release. This is an example of which mechanism for maintaining homeostasis?

    A. Negative feedback

    B. Positive feedback

    C. Stress response

    D. Parasympathetic regulation

    Answer Explanation

    Maintaining homeostasis means that conditions are kept stable and relatively constant. Negative feedback is a mechanism used to reverse or minimize changes in a system. In this example, negative feedback is used to keep the body's glucose and insulin levels stable. Positive feedback (B) is a mechanism that Increases changes in a system. A stress response (C) describes the body's reaction to threats or pressures. Parasympathetic regulation (D) refers to activities of the nervous system, including slowing the heart rate and boosting Intestinal activity.